Electronic pen

Abstract

To provide an electronic pen to which waterproof measures can be appropriately applied and of which the production procedures can be prevented from being complicated.SOLUTION: An electronic pen cartridge 1 is attached to an outer housing to form an electronic pen. A circuit board 16 and a pen pressure detection unit 14 are disposed in an inner casing 11. A core body 21 is disposed so as to press the pen pressure detection unit 14 in the inner housing 11. A coil 23 is disposed closer to a pen tip than the inner housing 11 but the coil 23 is at least covered with a resin-made sealing part 24. Accordingly, waterproof measures are applied to prevent a change in electric properties.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic pen that inputs information by specifying coordinates to various electronic devices equipped with a position detection sensor, such as a tablet PC (Personal Computer). [Background technology]

[0002] With the advent of various electronic devices equipped with position detection sensors, electronic pens have also become widely used. However, there has been a demand for electronic pens that can be used with electronic devices equipped with position detection sensors by attaching a refill with electronic pen functionality to the housing of a familiar writing instrument, such as a ballpoint pen, rather than a dedicated electronic pen. This has led to the development of an electronic pen that uses a cartridge-type refill with electronic pen functionality (hereinafter referred to as an electronic pen cartridge) that can be attached to the housing of an existing writing instrument.

[0003] Electronic devices equipped with position detection sensors are often carried and used in various locations, such as outdoors in the rain or near water such as the seashore or a river. For this reason, some electronic devices equipped with position detection sensors are designed to be waterproof. Correspondingly, waterproofing measures have also been considered for electronic pens. For example, Patent Document 1, described below, discloses a device in which components and a circuit board for realizing the electronic pen function are housed in a hollow portion of a cylindrical internal housing (cartridge case), and the hollow portion of the internal housing is filled with resin to achieve waterproofing and other measures.

[0004] In the electronic pen disclosed in Patent Document 1, the core can be attached to the internal housing so that the pen tip protrudes from the internal housing. The writing pressure detection unit is provided at the rear end of the internal housing, and the internal housing itself slides rearward in the axial direction in response to writing pressure applied to the core, and is pressed by a protrusion on the housing cover provided at the rear end, thereby enabling writing pressure detection. In the case of the invention disclosed in Patent Document 1, the components and circuit board required to realize the electronic pen function can be covered with resin, making it possible to realize an electronic pen with sufficient waterproofing measures. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2017 / 149879 Summary of the Invention [Problem to be solved by the invention]

[0006] The electronic pen of the invention disclosed in the aforementioned Patent Document 1 has a configuration in which a writing pressure detection unit is provided at the rear end of the internal housing. Therefore, the internal housing slides rearward in the axial direction within the external housing in response to writing pressure applied to the core, causing a convex portion of the housing lid attached to the rear end of the external housing to press the writing pressure detection unit of the internal housing. In this way, when the writing pressure detection unit is provided at the rear end of the internal housing, the writing pressure applied to the core is not directly pressed down on the writing pressure detection unit, so there is a concern that the writing pressure applied to the core may be dispersed along the way, resulting in a slight decrease in writing pressure detection responsiveness. Ideally, the writing pressure detection unit should be located on the pen tip side so that it can be directly pressed by the core.

[0007] For example, in the case of an electromagnetic induction electronic pen cartridge, electronic components such as a pressure sensor and a circuit board are housed within the internal housing, but the coil that forms the resonant circuit is often located upstream of the internal housing. In this configuration, where the coil is located outside the internal housing, waterproofing measures must be implemented for the coil. If the coil becomes wet, its characteristics may change, affecting the resonant frequency of the resonant circuit that includes the coil, which may affect the detection of the indicated position and the detection of the pressure on the position detection sensor side. It is also desirable to manufacture electronic pen cartridges with as little effort as possible.

[0008] In view of the above, an object of the present invention is to provide an electronic pen that is appropriately waterproofed and whose manufacturing process is not complicated. [Means for solving the problem]

[0009] In order to solve the above problems, A cylindrical ferrite core; a coil wound around a portion of the side surface of the ferrite core excluding a first non-wound portion in a certain range from one end to the other end in the longitudinal direction of the side surface of the ferrite core and a second non-wound portion in a certain range from the other end to the one end; a resin sealing formed to cover the coil, at least a portion of the coil side of the first non-wound portion, and at least a portion of the coil side of the second non-wound portion; The present invention provides an electronic pen capable of detecting a position by an electromagnetic induction method. [Brief explanation of the drawings]

[0010] [Figure 1] 2A and 2B are diagrams illustrating an electronic pen cartridge according to the first embodiment. [Figure 2] 10A and 10B are diagrams illustrating an electronic pen cartridge according to a second embodiment. [Figure 3]10A and 10B are diagrams illustrating another example of the electronic pen cartridge according to the second embodiment. [Figure 4] 10A and 10B are diagrams illustrating an electronic pen cartridge according to a third embodiment. [Figure 5] 10A and 10B are diagrams illustrating another example of the electronic pen cartridge according to the third embodiment. [Figure 6] 6 is a diagram for explaining an electrical connection portion between the tip unit of the electronic pen cartridge shown in FIG. 5 and the inner housing side. FIG. [Figure 7] FIG. 2 is a diagram showing an equivalent circuit of the electronic pen cartridge according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of an electronic pen cartridge according to the present invention will be described below with reference to the drawings. Position detection methods for electronic pens and position detection sensors include, for example, electromagnetic induction and capacitance. In the electromagnetic induction (EMR (Electro Magnetic Resonance)) method, the position detection device includes a sensor unit with multiple loop coils arranged in the X-axis and Y-axis directions. A transmission period in which power is sequentially supplied to the multiple loop coils of the sensor unit to generate a magnetic field is alternated with a reception period in which power supply is stopped and an external magnetic field is received. The corresponding electronic pen includes a resonant circuit consisting of a coil and a capacitor. In response to the magnetic field from the sensor unit, a signal is generated by current flowing through the coil. This signal, together with writing pressure information, is then transmitted to the position detection sensor. The position detection device receives this signal during the reception period to detect the position and writing pressure indicated by the electronic pen.

[0012] In the capacitance type, the position detection device is equipped with a sensor unit with multiple linear conductors (line electrodes) arranged in both the X-axis and Y-axis directions. The sensor unit detects the indicated position according to changes in capacitance (charge) generated in the linear conductors when a finger or electrostatic pen is brought close to the sensor unit. Electrostatic pens include conductive pen-type position indicators and so-called active electrostatic pens (AES (Active Electrostatic) type) that are battery-powered and transmit signals. In the case of the active electrostatic coupling type using an active electrostatic pen, the electronic pen transmits a signal from an oscillator circuit mounted on the electronic pen that also includes writing pressure information, which is received by the position detection device to detect the indicated position and writing pressure.

[0013] The electronic pen cartridge of this invention is suitable for use with an electromagnetic induction electronic pen cartridge, which includes a resonant circuit consisting of a coil and a capacitor, and in which the characteristics of the resonant circuit may change if the coil becomes wet. However, it can also be used with an active electrostatic coupling electronic pen cartridge, for example, if it includes a coil for contactlessly charging the installed battery. In other words, the electronic pen cartridge of this invention can be used with a coil connected to a circuit board, in which appropriate waterproofing measures must be taken for the coil portion. In the following embodiments, for simplicity, the invention will be described with reference to an example in which the invention is applied to an electromagnetic induction electronic pen cartridge.

[0014] The term "cartridge" refers to a device component that can be freely replaced. Therefore, an electronic pen cartridge has an external shape similar to that of a ballpoint pen refill, and corresponds to the refill that realizes the electronic pen function. Therefore, by attaching the electronic pen cartridge of this invention to the external housing (the shaft that houses the refill) of a ballpoint pen or the like, an electronic pen with a familiar ballpoint pen housing can be realized. The electronic pen cartridge of this invention will be specifically described below.

[0015] [First embodiment] FIG. 1 is a diagram illustrating an example of the configuration of an electronic pen cartridge 1 according to a first embodiment. FIG. 1(A) is a cross-sectional view of the electronic pen cartridge 1 according to the first embodiment, cut in half longitudinally and with the front portion removed. FIG. 1(B) is an external view of the electronic pen cartridge 1 shown in FIG. 1(A). As shown in FIG. 1(A), the electronic pen cartridge 1 is broadly composed of two parts: a main body part 1Bd and a tip unit part 1Ut.

[0016] The main body 1Bd is a portion configured by mounting various components inside an internal housing 11. The internal housing 11 is a cylindrical body with a hollow portion inside. The internal housing 11 has an opening on the pen tip side (the left end side in FIG. 1(A)) and a closed rear end side (the right end side in FIG. 1(A)) to form a bottom surface, and a rod-shaped connecting portion 11a is formed in the outer central portion of the bottom surface, extending further toward the rear end in a rod shape. The rod-shaped connecting portion 11a is intended to be attached to the inside of an outer housing of, for example, a ballpoint pen that is held by a user.

[0017] A tip cap 12 is provided at the opening on the pen tip side of the internal housing 11, and a substrate holder 15 is provided behind the tip cap 12. The substrate holder 15 is an elongated component that includes a tip tubular portion 15a on the pen tip side, a thick intermediate bottom portion 15b behind it that forms the bottom surface of the tip tubular portion 15a, and a plate-like portion 15c extending rearward from the rear end surface of the intermediate bottom portion 15b. Furthermore, the substrate holder 15 includes a thick rear bottom portion 15d at the rear end of the plate-like portion 15c, the rear end surface of which abuts against the inner bottom surface of the internal housing. The intermediate bottom portion 15b and the rear bottom portion 15d are circular, flat portions with a diameter slightly shorter than the inner diameter of the internal housing 11.

[0018] The tip cap 12 is a cylindrical body formed by connecting two cylindrical portions of different diameters. The outer diameter of the longer-diameter cylindrical portion of the tip cap 12 is the same as or slightly longer than the inner diameter of the internal housing 11, and the longer-diameter cylindrical portion of the tip cap 12 is fitted into the tip opening of the internal housing 11 and fixed thereto. The outer diameter of the shorter-diameter cylindrical portion of the tip cap 12 is the same as or slightly longer than the inner diameter of the tip cylindrical portion 15a of the substrate holder 15, and the shorter-diameter cylindrical portion of the tip cap 12 is fitted into the tip cylindrical portion 15a of the substrate holder 15 from the opening on the pen tip side. As a result, the substrate holder 15 is sandwiched between the tip cap 12 and the bottom surface of the internal housing 11 and fixed within the hollow portion of the internal housing 11. As will be described later, the rear end side of the ferrite core 22 is fitted into the longer-diameter cylindrical portion of the tip cap 12 from the pen tip side.

[0019] A cap-shaped pusher member 13 is provided behind the tip cap 12. As will be described later, the rear end of the core body 21 is attached to the pusher member 13, and functions to hold the core body 21 within the internal housing 11. The core body 21 is made up of a pen tip portion 21a formed so as to have a rounded tip, and a shaft portion 21b extending in a rod shape from the pen tip portion 21a toward the rear end. A writing pressure detection unit 14 is provided behind the pusher member 13, sandwiched between the pusher member 13 and the intermediate bottom portion 15b of the tip tubular portion 15a of the substrate etc. holder 15.

[0020] The writing pressure detection unit 14 is configured as a MEMS (Micro Electro Mechanical Systems) sensor. The writing pressure detection unit 14 is pressed by the core body 21 and the pusher member 13, and detects the writing pressure applied to the core body 21 as, for example, a change in capacitance. A coil spring 13a is provided around a portion of the outer side surface (external wall surface) of the pusher member 13, and when the writing pressure applied to the core body 21 is released, the restoring force of the coil spring 13a pushes the core body 21 back to its original position.

[0021] 1(A), a circuit board 16 is placed and fixed on the top surface of a board holder 15. Various circuit components, such as a capacitor 16a and a control IC (Integrated Circuit) 16b, are mounted on the circuit board 16 as main components to form a circuit section. As shown in FIG. 1(A), an electrode 16c connected to the writing pressure detection section 14 is provided on the pen tip side of the circuit board 16, and this electrode 16c and the circuit section formed on the circuit board 16 are electrically connected by a conductive section 16d.

[0022] Furthermore, the circuit board 16 is provided with a fixing hole that penetrates the circuit board 16 in the thickness direction at a predetermined position on the pen tip side. As shown in FIG. 1(A), when the circuit board 16 is placed in a fixed position in the board etc. folder 15, a fixing protrusion 15e provided on the board etc. folder 15 fits into the fixing hole. This fixes the position of the circuit board 16 on the board etc. folder 15. In this way, the tip cap 12, the plunger member 13, the writing pressure detection unit 14, the board etc. folder 15, and the circuit board 16 are mounted inside the internal housing 11, as shown in FIG. 1(A), to form the main body 1Bd.

[0023] On the other hand, the tip unit 1Ut is provided in front of the main body 1Bd (on the pen tip side). The tip unit 1Ut includes a ferrite core 22, which is a cylindrical body having a through-hole through which the core 21 passes, and a coil 23 formed by winding a coated conductor wire around the side surface of the ferrite core 22. In the first embodiment, as shown in FIG. 1(A), a first unwound portion 22a and a second unwound portion 22b are provided at both ends of the ferrite core 22, i.e., at a certain range on the pen tip side and the rear end side, where no coated conductor wire is wound and no coil is formed, respectively.

[0024] 1(A), the tip unit 1Ut has a sealing portion 24 formed therein so as to cover the coil 23, a portion of the first unwound portion 22a on the coil 23 side, and a portion of the second unwound portion 22b on the coil 23 side. The sealing portion 24 is made of a resin such as plastic and covers the entire coil 23, thereby providing a waterproof function to the coil 23 portion. Specifically, the coil 23 formed on the side surface of the ferrite core 22 is integrated by being wrapped in the sealing portion 24 made of a resin material by so-called insert molding.

[0025] That is, insert molding is a molding method in which heated and melted resin such as plastic is injected around a part inserted into an injection mold, integrating the inserted part with the injected resin. In this way, by integrating the part (part of the ferrite core 22 and the coil 23) with the resin (sealing portion 24), the part can be isolated from the outside world by the resin, providing waterproofing. The second unwound portion 22b of the ferrite core 22 of the tip unit portion 1Ut formed in this way is fitted and fixed into the long-diameter cylindrical portion of the tip cap 12 of the main body portion 1Bd.

[0026] The outer diameter of ferrite core 22 is approximately the same as the inner diameter of the longer-diameter cylindrical portion of tip cap 12. For this reason, in the first embodiment, second unwound portion 22b of ferrite core 22 and the longer-diameter cylindrical portion of tip cap 12 are bonded together with an adhesive such as a two-component epoxy adhesive. Note that conductive wires 23a, 23b extending from both ends of coil 23 are led onto circuit board 16 along the inner side surface of inner housing 11 and connected to a circuit portion formed on circuit board 16, as shown in FIG. 1(A).

[0027] In this way, the tip unit portion 1Ut is attached to the main body portion 1Bd, and the core 21 is inserted and pushed in from the rear end side of the shaft portion 21b through the tip opening of the ferrite core 22. As a result, as shown in FIG. 1(A), the rear end of the shaft portion 21b of the core 21 is attached to the pusher member 13 of the main body portion 1Bd, thereby forming the electronic pen cartridge 1. As shown in FIG. 1(B), the external appearance of the electronic pen cartridge 1 has a configuration in which the main body portion 1Bd and the tip unit portion 1Ut are connected, and the pen tip portion 21a of the core 21 protrudes from the first unwound portion 22a side of the ferrite core 22 of the tip unit portion 1Ut. The core 21 is detachable and can be replaced as needed.

[0028] In the case of the electronic pen cartridge 1 of the first embodiment, the entire coil 23 of the tip unit 1Ut is sealed off from the outside world by the sealing portion 24, thereby providing a waterproof function. Therefore, when the electronic pen cartridge 1 is mounted in an external housing such as the housing of a ballpoint pen, a waterproof electronic pen can be realized. The electronic pen cartridge 1 of the first embodiment has, for example, a diameter of 3.8 mm and a total length in the longitudinal direction of 65.65 mm, which is approximately the same size as a commercially available ballpoint pen refill.

[0029] 1, in order to clarify the configuration including the main body portion 1Bd and the tip unit portion 1Ut, a gap is provided between the main body portion 1Bd and the sealing portion 24 when the main body portion 1Bd and the tip unit portion 1Ut are connected. However, this is not limited to this. Of course, it is also possible to configure the sealing portion 24 so that it extends further to the rear end so as to cover more of the second non-wound portion 22b, thereby joining the rear end surface of the sealing portion 24 and the front end surface of the main body portion 1Bd.

[0030] [Second embodiment] The electronic pen cartridge 1 of the first embodiment described above has a configuration in which the main body 1Bd and the tip unit 1Ut are bonded together with an adhesive. This necessarily requires a bonding process, and also requires time for drying and curing the bond, which may result in insufficient manufacturing efficiency. Therefore, the electronic pen cartridge 1A of the second embodiment eliminates the bonding process and eliminates the need for drying and curing the bond.

[0031] FIG. 2 is a diagram illustrating an example of the configuration of an electronic pen cartridge 1A according to a second embodiment. FIG. 2(A) is a cross-sectional view of the electronic pen cartridge 1A according to the second embodiment, cut in half lengthwise and with the front portion removed. FIG. 2(B) is an external view of the electronic pen cartridge 1A shown in FIG. 2(A). As can be seen from a comparison between FIG. 2(A) and FIG. 1(A), the electronic pen cartridge 1A according to the second embodiment shown in FIG. 2 has components for realizing the electronic pen function that are similar in configuration to the electronic pen cartridge 1 according to the first embodiment described using FIG. 1.

[0032] For this reason, in the electronic pen cartridge 1A of the second embodiment shown in Fig. 2, the same reference numerals are used to designate parts that are configured in the same way as the electronic pen cartridge 1 of the first embodiment described with reference to Fig. 1, and detailed descriptions of these parts will be omitted to avoid duplication. The electronic pen cartridge 1A of the second embodiment also has a main body portion 1Bd and a tip unit portion 1Ut, just like the electronic pen cartridge 1 of the first embodiment described with reference to Fig. 1.

[0033] As shown in FIG. 2A, the main body 1Bd is configured by mounting a tip cap 12, a plunger member 13, a pen pressure detection unit 14, a board holder 15, and a circuit board 16 within an internal housing 11. The tip unit 1Ut is provided in front of the main body 1Bd and includes a ferrite core 22, which is a cylindrical body having a through-hole through which a core 21 passes, and a coil 23 formed by winding a coated conductor wire around the side of the ferrite core 22. As shown in FIG. 2A, the ferrite core 22 has a first unwound portion 22a and a second unwound portion 22b at certain ranges on the pen tip side and rear end side, where no coated conductor wire is wound and no coil is formed. This is also similar to the electronic pen cartridge 1 of the first embodiment.

[0034] In the electronic pen cartridge 1A of the second embodiment, the second unwound portion 22b of the ferrite core 22 of the tip unit portion 1Ut is fitted into and fixed to the long-diameter cylindrical portion of the tip cap 12 of the main body portion 1Bd. However, in the electronic pen cartridge 1A of the second embodiment, it is not necessary to bond the joint between these two with, for example, a two-component epoxy adhesive. With the main body portion 1Bd and the tip unit portion 1Ut joined together, the sealing portion 24A is formed by covering their peripheries with a resin material such as plastic by insert molding.

[0035] That is, sealing portion 24A includes a portion of first unwound portion 22a of ferrite core 22 and covers the entire inner housing 11 up to the rear end surface. However, in this second embodiment, sealing portion 24A does not cover the entire rod-shaped connecting portion 11a provided in the outer central portion of the bottom surface of inner housing 11, but only covers the outer portion of the bottom surface. In other words, sealing portion 24A covers the entire inner housing 11 except for the pen tip side portion of first unwound portion 22a of ferrite core 22 and rod-shaped connecting portion 11a provided on the outer side of the bottom surface.

[0036] 2(B), the entire electronic pen cartridge 1A, including the connection between the main body 1Bd and the tip unit 1Ut, can be covered with the sealing portion 24A, thereby realizing an electronic pen cartridge 1A in which the connection is not exposed. In this case, a strong waterproof function can be added to almost the entire electronic pen cartridge 1A, including the coil 23. Moreover, there is no need to use adhesive to bond the connection between the main body 1Bd and the tip unit 1Ut, which improves manufacturing efficiency.

[0037] [Another Example of the Second Embodiment] 3A and 3B are diagrams illustrating an example of the configuration of an electronic pen cartridge 1AX according to another example of the second embodiment. FIG. 3A is a cross-sectional view of the electronic pen cartridge 1AX according to another example of the second embodiment, cut in half longitudinally and with the front portion removed. FIG. 3B is an external view of the electronic pen cartridge 1AX shown in FIG. 3A. The electronic pen cartridge 1AX shown in FIG. 3 is configured in substantially the same manner as the electronic pen cartridge 1A according to the second embodiment described with reference to FIG. 2.

[0038] However, the configurations of the internal housing 11A and the sealing portion 24B are different from those of the internal housing 11 and the sealing portion 24A of the electronic pen cartridge 1A in Fig. 2. For this reason, in another example of the electronic pen cartridge 1AX shown in Fig. 3, the same reference numerals are used for parts configured in the same way as the electronic pen cartridge 1A shown in Fig. 2, and a description of these parts will be omitted, and only the parts with different configurations will be described in detail.

[0039] In another example of the second embodiment of the electronic pen cartridge 1AX shown in FIG. 3(A), the inner housing 11A of the main body 1BdA does not have a rod-shaped connecting portion 11a formed on the outer surface of the bottom of the rear end. The outer surface of the bottom of the inner housing 11A is flat. However, a rod-shaped connecting portion 24Ba is formed integrally with the sealing portion 24B on the outer side of the bottom of the sealing portion 24B. That is, in the case of the electronic pen cartridge 1AX of another example of the second embodiment shown in FIG. 3, a rod-shaped connecting portion 24Ba extending toward the rear end is formed integrally with the sealing portion 24B at the center of the outer surface of the bottom of the sealing portion 24B formed by insert molding.

[0040] This allows the inner housing 11A to have a simple configuration without the rod-shaped connecting portion 11a, and also allows the rod-shaped connecting portion 24Ba for attachment to the outer housing to be formed as part of the sealing portion 24B formed by insert molding. In this case, the appearance of the electronic pen cartridge 1AX shown in Figure 3(B) can be configured to be the same as the appearance of the electronic pen cartridge 1A shown in Figure 2(B). This allows for simplification of the manufacturing process for the electronic pen cartridge.

[0041] [Third embodiment] In the electronic pen cartridge 1 of the first embodiment described with reference to Fig. 1, the main body 1Bd and the tip unit 1Ut are bonded together with an adhesive, and therefore cannot be separated after bonding. In the electronic pen cartridges 1A and 1AX of the second embodiment described with reference to Figs. 2 and 3, the entire electronic pen cartridge is covered with sealing portions 24A and 24B, and therefore the main body 1Bd and 1BdA and the tip unit 1Ut cannot be separated after formation.

[0042] However, if the main body and the tip unit are formed separately and then tightly connected so as to be detachable, assembly would be easier, and if there is a problem with either the main body or the tip unit, the defective one could be replaced. It would also be possible to replace parts of the main body. Therefore, the electronic pen cartridge 1B of the third embodiment described below is configured so that the main body and the tip unit are formed separately and then tightly connected so as to be detachable.

[0043] 4A and 4B are diagrams illustrating an example of the configuration of an electronic pen cartridge 1B according to a third embodiment. FIG. 4A is a cross-sectional view of the electronic pen cartridge 1B according to the third embodiment, cut in half longitudinally and with the front portion removed. FIG. 4B is an external view of the electronic pen cartridge 1B shown in FIG. 4A. FIG. 4C is an external view of only the tip unit portion 1UtB of the electronic pen cartridge 1B shown in FIG. 4B.

[0044] In the case of the electronic pen cartridge 1B of the third embodiment, the configuration of the parts that realize the electronic pen function is the same as that of the electronic pen cartridge 1 of the first embodiment and the electronic pen cartridges 1A and 1AX of the second embodiment described above. For this reason, in the electronic pen cartridge 1B of the third embodiment shown in Figure 4, parts that are configured in the same way as the electronic pen cartridges 1, 1A and 1AX of the first and second embodiments described above are given the same reference numerals, and detailed description of these parts will be omitted.

[0045] As shown in FIG. 4A, the electronic pen cartridge 1B of the third embodiment also includes a main body 1BdB and a tip unit 1UtB. The tip unit 1UtB is provided with a coil 23 by winding a coated conductor around the center of the side of a ferrite core 22, which is a cylindrical body having a through-hole through which the core 21 passes. Therefore, a certain range from one longitudinal end (the end toward the pen tip) of the ferrite core 22 to the other longitudinal end (the end toward the rear end) is a first unwound portion 22a where no coil is formed. Similarly, a certain range from the other longitudinal end (the end toward the rear end) to one longitudinal end (the end toward the pen tip) is a second unwound portion 22b where no coil is formed.

[0046] Furthermore, a sealing portion 24C is provided so as to cover the coil 23, a portion of the first unwound portion 22a of the ferrite core 22 facing the coil 23, and the entire second unwound portion 22b. Unlike the sealing portion 24 of the electronic pen cartridge 1 of the first embodiment, the sealing portion 24C includes a joint portion 24Ca at the rear of the second unwound portion 22b. The joint portion 24Ca has a through-hole through which the core body 21 passes, which passes through the through-hole of the ferrite core 22, and is a protruding portion that protrudes toward the rear end and is formed with a screw thread for connection to the internal housing 11B.

[0047] 4(C), the tip unit part 1UtB covers a part of the first unwound part 22a of the ferrite core 22 on the coil 23 side, the coil 23, and the entire second unwound part 22b, and is provided with a joint part 24Ca protruding toward the rear end. In this way, the tip unit part 1UtB is formed by integrally insert molding the part covering the coil 23 and the joint part 24Ca having a screw thread.

[0048] 4(A), the inner housing 11B of the third embodiment has a connecting portion 11Ba formed in its pen tip opening with threads that correspond to the threads of the joint portion 24Ca formed in the sealing portion 24C of the tip unit portion 1UtB. A retaining ring 12A is fitted into the opening of the tip tubular portion 15a of the board holder 15 to secure the plunger member 13 within the tip tubular portion 15a of the board holder 15. In other words, the outer diameter of the retaining ring 12A is the same as or slightly longer than the inner diameter of the tip tubular portion 15a.

[0049] As a result, as shown in Fig. 4(A), the joint portion 24Ca of the sealing portion 24C can be screwed onto the connecting portion 11Ba formed by providing a screw thread at the opening of the inner housing 11B, by rotating it. Therefore, as shown in Fig. 4(B), a single electronic pen cartridge 1B can be formed in which the main body portion 1BdB and the tip unit portion 1UtB are tightly connected.

[0050] In this case, the coil 23 side of the first unwound portion 22a of the ferrite core 22, the coil 23, and the entire second unwound portion 22b are covered by the sealing portion 24C, so this portion can be firmly waterproofed. Moreover, the tip unit portion 1UtB and the internal housing 11B are connected with screws, so water or the like cannot get into the internal housing 11B through the tip opening of the internal housing 11B. Therefore, a strong waterproofing function can be provided for the entire electronic pen cartridge 1B of the third embodiment.

[0051] 4(C), conductive wires 23a and 23b are led out from both ends of the coil 23 from the tip unit 1UtB. These conductive wires 23a and 23b are extended toward the inner housing 11B, for example, through a groove provided in the longitudinal direction on the side surface of the inner housing 11B, and connected to a circuit section formed on the circuit board 16 inside the inner housing 11B. In practice, the conductive wires from the circuit section formed on the circuit board 16 inside the inner housing 11B can be led out in advance to the groove provided on the side surface of the inner housing 11B, and the conductive wires 23a and 23b from the coil 23 of the tip unit 1UtB can be connected to this.

[0052] The conductive wires from the circuit portion formed on the circuit board 16 can be connected to the conductive wires 23a, 23b from the coil 23 in a variety of ways. For example, if a ring-shaped terminal for connection is provided at the tip of the conductive wire fed into the groove in the side surface of the inner casing 11B and the conductive wires 23a, 23b from the coil 23 are hooked onto this terminal, connection can be easily achieved. Of course, other connection methods are also possible. In short, various connection methods that allow for easy connection without much effort can be adopted.

[0053] [Modification of the third embodiment] As described above, in the case of the electronic pen cartridge 1B of the third embodiment, the conductive wires extending from both ends of the coil 23 are connected to the circuit portion of the circuit board 16 on the outer side surface of the internal housing. This requires a process for connecting the coil 23 to the circuit portion, and when connecting on the outer side surface of the internal housing 11B, a separate waterproofing treatment must be applied to the portion of the conductive wire that runs along the outer side surface. Therefore, in this modified example of the third embodiment, the coil 23 is connected to the circuit portion of the circuit board 16 inside (inside) the internal housing.

[0054] Fig. 5 is a cross-sectional view of another example of the third embodiment of the electronic pen cartridge 1BX, cut in half lengthwise and with the front portion removed, showing an enlarged view of the connection between the main body 1BdC and the tip unit 1UtC. Fig. 6 is a diagram illustrating the configuration of the rear end surface of the joint 24Da of the tip unit 1UtC and the tip surfaces of the tip tubular portion 15a and the retaining ring 12A of the main body 1BdC.

[0055] Note that the electronic pen cartridge 1BX of another example of the third embodiment shown in Fig. 5 is configured in almost the same manner as the electronic pen cartridge 1B of the third embodiment described with reference to Fig. 4. For this reason, in Fig. 5, parts configured in the same manner as the electronic pen cartridge 1B of the third embodiment shown in Fig. 4 are given the same reference numerals, and detailed description of those parts will be omitted.

[0056] As shown in FIG. 5, in the tip unit 1UtC, the conductive wire 23a extending from one end of the coil 23 is connected to an electrode 25a provided on the rear end surface of the joint portion 24Da. Similarly, the conductive wire 23b extending from the other end of the coil 23 is connected to an electrode 25b provided on the rear end surface of the joint portion 24Da. That is, as shown in FIG. 6(A), electrodes 25a and 25b are provided on the rear end surface (the end surface exposed to the outside) of the joint portion 24D formed by insert molding as part of the sealing portion 24D, at positions facing each other across a through hole HN through which the core passes. As shown in FIG. 6(A), the conductive wire 23a extending from one end of the coil 23 is connected to the electrode 25a, and the conductive wire 23b extending from one end of the coil 23 is connected to the electrode 25b.

[0057] In this way, the joint part 24Da is formed as a part of the sealing part 24D, similar to the joint part 24Ca of the electronic pen cartridge 1B of the third embodiment shown in Fig. 4. However, the joint part 24Da is different from the tip unit part 1UtB shown in Fig. 4 in that it has electrodes 25a and 25b on the rear end surface, to which conductive wires 23a and 23b from the coil are connected through the inside of the joint part 24Da.

[0058] On the other hand, as shown in Fig. 5, conductive wires 16e and 16f extending from a circuit portion formed on circuit board 16 mounted in inner housing 11B are connected to electrodes 17a and 17b provided on the distal end surfaces of distal tube portion 15a and retaining ring 12A of main body 1BdC. Specifically, as shown in Fig. 6(B), electrodes 17a and 17b are provided on the distal end surfaces of distal tube portion 15a and retaining ring 12A at positions facing each other across hole HB, into which the core body is inserted. As shown in Fig. 6(B), conductive wire 16e extending from the circuit portion is connected to electrode 17a, and conductive wire 16f extending from the circuit portion is connected to electrode 17b.

[0059] The rear end surface of the joint portion 24Da shown in FIG. 6(A) and the front end surface of the tip tubular portion 15a and the retaining ring 12A shown in FIG. 6(B) are surfaces that face each other when the tip unit portion 1UtC is screwed onto the connecting portion 11Ba of the main body portion 1BdC. Assume that the joint portion 24Da is fully inserted into the connecting portion 11Ba of the main body portion 1BdC while rotating. In this case, the electrode 25a on the rear end surface of the joint portion 24Da faces and contacts the electrode 17a on the front end surface of the tip tubular portion 15a and the retaining ring 12A. Similarly, the electrode 25b on the rear end surface of the joint portion 24Da faces and contacts the electrode 17b on the front end surface of the tip tubular portion 15a and the retaining ring 12A.

[0060] This electrically connects the coil 23 of the tip unit 1UtC to the circuitry on the circuit board 16 mounted on the internal housing. Thus, in the case of the electronic pen cartridge 1BX of this other example of the third embodiment, simply by screwing the joint portion 24Da to the connecting portion 11Ba of the main body 1BdC, the coil 23 can be electrically connected to the circuitry on the circuit board 16. Therefore, unlike the case of the electronic pen cartridge 1B of the third embodiment described with reference to FIG. 4, there is no need to connect the conductive wires extending from both ends of the coil 23 to the circuitry on the circuit board 16 on the side of the internal housing. This allows for an electronic pen cartridge 1BX with a simple connection process.

[0061] [Equivalent circuit of electronic pen cartridge] Fig. 7 is a diagram showing the equivalent circuit of the electronic pen cartridges 1, 1A, 1AX, 1B, and 1BX of the first, second, and third embodiments described above. As shown in Fig. 7, the electronic pen cartridges 1, 1A, 1AX, 1B, and 1BX have a configuration in which a coil (inductor) 23, a capacitor 16a, and a pen pressure detection unit 14 configured as a variable capacitor are connected in parallel.

[0062] This allows the coil 23 and capacitor 16a to form a resonant circuit, receive a signal from an electromagnetic induction-type position detection sensor, generate a transmission signal, and transmit this to the position detection sensor to indicate the position. Furthermore, by providing the pen pressure detection unit 14 configured as a variable capacitor, the transmission signal sent from the electronic pen cartridge 1, 1A, 1AX, 1B, or 1BX can include information indicating the pen pressure, for example, as a change in the phase of the transmission signal. In this way, each of the electronic pen cartridges 1, 1A, 1AX, 1B, or 1BX can function as an electromagnetic induction-type electronic pen.

[0063] [Effects of the embodiment] In the case of the electronic pen cartridge 1 of the first embodiment described above, the coil 23, which is located closer to the pen tip than the main body 1Bd, can be tightly covered with the resin sealing part 24, thereby providing an appropriate waterproof function. Therefore, even if the electronic pen cartridge 1 is submerged in water, there will be no inconvenience such as a change in the resonant frequency of the resonant circuit including the coil 23.

[0064] In the case of the electronic pen cartridges 1A and 1AX of the second embodiment described above, the entire tip unit portion 1Ut and the main body portion 1Bd or 1BdA, including the coil 23, can be covered with resin sealing portions 24A and 24B, thereby providing a waterproof function to the entire tip unit portion 1Ut and the main body portion 1Bd or 1BdA.

[0065] Moreover, since the entire cartridge is covered with the sealing portions 24A and 24B, there is no need to use adhesive to bond the main body 1Bd or 1BdA to the tip unit 1Ut, and there is no need to allow time for the adhesive to harden. This means that the manufacturing process can be simplified and the manufacturing time can be shortened. Furthermore, in the case of another example of the electronic pen cartridge 1AX of the second embodiment, the rod-shaped connecting portion 24Ba for connecting to the external housing can also be formed as part of the sealing portion 24B, further simplifying the manufacturing process.

[0066] Furthermore, in the case of the electronic pen cartridge 1B, 1BX of the third embodiment described above, the main body 1BdB or 1BdC and the tip unit 1UtB, 1UtC can be connected by screws. This makes it possible to manufacture the main body 1BdB or 1BdC and the tip unit 1UtB, 1UtC separately and then simply connect them by screws, thereby simplifying the manufacturing process. Moreover, the main body 1BdB or 1BdC and the tip unit 1UtB, 1UtC can be separated at any time, making it possible to replace either one if a problem occurs.

[0067] Furthermore, in the case of another example of the electronic pen cartridge 1BX of the third embodiment, if the main body portion 1BdC and the tip unit portion 1UtC are joined together with screws, the coil 23 can be electrically connected to the circuit portion formed on the circuit board 16. This makes it possible to further simplify the manufacturing process.

[0068] [Variations] In the above embodiment, the size of the electronic pen cartridge 1 has been described as being 3.8 mm in diameter and 65.65 mm in overall length, but this is just an example and is not limited to this. The size of the electronic pen cartridge can be adjusted in various ways.

[0069] Furthermore, in the above-described embodiment, the present invention has been described as being applied to an electromagnetically coupled electronic pen, but is not limited to this. As described above, the present invention can also be applied to an active capacitance type electronic pen, for example, an electronic pen cartridge having a coil on the pen tip side for charging the battery, in which case waterproofing of the coil is added.

[0070] 5 and 6, the positions and shapes of the electrodes 25a, 25b and the electrodes 17a, 17b can be variously changed. That is, various modes are possible as long as the coil 23 and the circuit portion of the circuit board 16 can be reliably electrically connected when the tip unit portion 1UtC and the main body portion 1BdC are connected.

[0071] Furthermore, the internal housing may be a so-called pipe-like structure having a hollow portion, and its external appearance may be of various shapes, such as a cylindrical shape or a polygonal prism shape. Of course, the external housing into which the electronic pen cartridge of this invention is mounted may also be a so-called pipe-like structure having a hollow portion into which the electronic pen cartridge can be mounted. Therefore, the external appearance of the external housing may of course be a so-called pipe-like structure having a hollow portion into which the electronic pen cartridge can be mounted. [Explanation of symbols]

[0072] 1, 1A, 1AX, 1B, 1BX...electronic pen cartridge, 1Bd, 1BdA, 1BdB, 1BdC...main body, 1Ut, 1UtB, 1UtC...tip unit, 11, 11A, 11B...internal housing, 11Ba...connection portion, 11a...rod-shaped connection portion, 12...tip cap, 12A...retaining ring, 13...push member, 13a...coil spring, 14...pen pressure detection portion, 15...substrate etc. folder, 15a...tip cylindrical portion, 15b...middle bottom portion, 15c...plate-shaped portion, 15d...rear end bottom portion, 15e... Fixed protrusion, 16...circuit board, 16a...capacitor, 16b...control IC, 16c...electrode, 16d...conductive portion, 16e, 16f...conductive wire, 17a, 17b...electrode, 21...core body, 21a...pen tip portion, 21b...shaft portion, 22...ferrite core, 22a...first unwound portion, 22b...second unwound portion, 23...coil, 23a, 23b...conductive wire, 24, 24A, 24B, 24C, 24D...sealing portion, 24Ba...rod-shaped connecting portion, 24Ca, 24Da...joint portion, 25a, 25b...electrodes

Claims

1. A cylindrical ferrite core; a coil wound around a portion of the side surface of the ferrite core excluding a first non-wound portion extending from one end to the other end in a longitudinal direction of the side surface of the ferrite core and a second non-wound portion extending from the other end to the one end in a longitudinal direction of the side surface of the ferrite core; a resin sealing formed to cover the coil, at least a portion of the coil side of the first non-wound portion, and at least a portion of the coil side of the second non-wound portion; An electronic pen capable of detecting position using an electromagnetic induction method.

2. Further provided with a rod-shaped core body, The ferrite core is provided with a through hole through which the core body passes. The electronic pen according to claim 1 .

3. Further comprising a pen pressure detection unit, The core body presses the writing pressure detection unit. The electronic pen according to claim 2 .

4. Further, a circuit board to which both ends of the coil are connected is provided, The coil forms a resonant circuit by connecting a capacitor element mounted on the circuit board and the writing pressure detection unit in parallel.

4. The electronic pen according to claim 3.

5. The housing and a circuit board housed in the housing and to which both ends of the coil are connected; The electronic pen of claim 1 further comprising:

6. The sealing is formed to integrally cover the inner housing together with the coil. The electronic pen according to claim 5 .

7. a cylindrical ferrite core having a through hole through which a rod-shaped core body can be inserted and removed from one end side; a coil wound around a portion of the side surface of the ferrite core excluding a non-wound portion within a certain range from the other end to the one end in the longitudinal direction of the side surface of the ferrite core; a resin sealing member formed to cover the coil and at least a portion of the non-wound portion on the coil side; An electronic pen capable of detecting position using an electromagnetic induction method.

Images