Electromagnetic induction pen

Abstract

The present invention realizes an electromagnetic induction pen capable of obtaining an appropriate magnetic field distribution without reducing the strength of a housing, and performing instruction input to a drawing device so as to apply a wide range when the pen is used in a state of being inclined to be approximately horizontal. The present invention is provided with a housing (120) having an opening at one end. A pen pressure detection part (150) is fixed in the housing (120). A columnar threaded core (131) wound with a coil (132) and having a through-hole is provided at the front section (tip side) of the pen pressure detection unit (150). A core body is provided, the core body including a core rod (112) that passes through a through hole of the ferrite core (131) in a gap and transmits force to the pen pressure detection unit (150), and a wall portion (113) having an inner wall (111n) facing a side surface (131a) on the tip side of the ferrite core (131) along a predetermined length in the axial direction of the housing (120).

Description

Technical Field

[0001] The present invention relates to an electromagnetic induction pen that functions as a position indicator for an electromagnetic induction position detection device. Background Art

[0002] For example, when sketching with a pencil, when drawing with large areas, such as with shading, the pencil is tilted nearly horizontally relative to the paper surface. Specifically, by tilting the pencil 25 to 30 degrees relative to the recording medium and drawing with the side of the graphite portion of the pencil, it is possible to draw with large areas. In recent years, the use of electronic pens to digitally draw (input) drawings on drawing devices such as tablet computers has been increasing. Therefore, when using an electronic pen to draw on a drawing device, similar to the pencil method described above, it is also desirable to use an electronic pen for large-scale drawing.

[0003] In order for the drawing device to reflect the input using the electronic pen, the electronic pen must be detected by a position detection device built into the drawing device. The position detection device detects the position of the pen tip of the electronic pen and the value of the pen pressure applied to the pen tip. The pen pressure of the electronic pen is detected by the core pressing the pen pressure detection unit inside the electronic pen according to the pen pressure. Usually, when writing on a recording medium such as paper with a writing tool such as a pencil, the writing tool is tilted at an angle of 60 to 80 degrees relative to the recording medium to write the text. In this state, when using the electronic pen to input characters to the position detection device, the pressing force of the pen tip is transmitted to the core and presses the pen pressure detection unit.

[0004] However, when using an electronic pen in a drawing method such as applying a shadow to an object drawn on a recording medium by tilting (tilting) the writing implement at 25 to 30 degrees, the core body flexes in a direction intersecting the pen's axis, preventing the pen pressure from being transmitted to the pen pressure detection unit. Therefore, Patent Document 1, described later, discloses an electronic pen having a cylindrical housing with a surface formed by a fitting groove or the like facing the inner or outer surface of the core body's recess. This allows the core body to press the pen pressure detection unit even when the electronic pen is tilted. In this case, the surface formed by the fitting groove or the like provided in the housing faces the inner or outer surface of the core body's recess, preventing the core body from flexing in a direction intersecting the pen's axis, and the pen pressure applied to the pen tip of the core body is appropriately transmitted to the pen pressure detection unit.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 7154209 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] In the case of the electronic pen disclosed in Patent Document 1, it is believed that a fitting groove or the like is provided in the housing, or processing is performed to form a surface. Depending on the method of providing the fitting groove or the like, the strength of the housing may sometimes be reduced. Furthermore, in the case of an electromagnetic induction electronic pen (electromagnetic induction pen), a resonant circuit consisting of a coil and a capacitor is mounted. However, how the magnetic body (ferrite core) around which the coil is wound is arranged relative to the housing is an important issue in order to obtain the desired magnetic field distribution on the position detection device side. Furthermore, if the positional relationship between the magnetic body around which the coil is wound and the core is not properly determined, the desired magnetic field distribution cannot be obtained. Furthermore, depending on the arrangement of the magnetic body (ferrite core) relative to the housing, it is also necessary to appropriately determine the method of mounting the magnetic body to the housing.

[0010] In view of the above situation, the purpose of the present invention is to realize an electromagnetic induction pen that can obtain appropriate magnetic field distribution without reducing the strength of the shell, and when used in a tilted state close to horizontal, can provide indication input to a drawing device by smearing a large area.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, an electromagnetic induction pen is provided, comprising: a shell having an opening at one end; a pen pressure detection unit fixed to the shell; a columnar magnetic body wound with a coil and having a through hole; and a core body, comprising a core rod that passes through the through hole and transmits force to the pen pressure detection unit, and a wall portion having an inner wall that is opposite to the columnar side surface of the magnetic body along a specified length in the axial direction of the shell. The electromagnetic induction pen uses the magnetic body to form a magnetic field.

[0013] In addition, in order to solve the above-mentioned problems, an electromagnetic induction pen is provided, comprising: a shell having an opening at one end; a core body having a front end portion and a core rod; a magnetic body formed into a columnar shape in a manner for winding a coil, having a hole for the core rod to pass through, and arranged at a position where the front end side is exposed from the opening portion when the core body is removed; and a magnetic body holder fixed to the shell, having a fixing portion for fixing the rear end side of the magnetic body in a manner that the magnetic body will not be pulled out from the opening portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 These are diagrams for explaining an example of the appearance of an electromagnetic induction pen according to an embodiment and an example of the appearance of a tablet-type information terminal that uses the electromagnetic induction pen to input information.

[0015] Figure 2This is an external view of the connection portion between the core and the housing of the electromagnetic induction pen according to the first embodiment ( Figure 2 (A)) and cross-sectional view ( Figure 2 (B)).

[0016] Figure 3 This is an external view of the connection portion between the core and the housing of the electromagnetic induction pen according to the second embodiment ( Figure 3 (A)) and cross-sectional view ( Figure 3 (B)).

[0017] Figure 4 This is a diagram for explaining the dimensions of various parts on the pen tip side of the second electromagnetic induction pen.

[0018] Figure 5 This is a diagram for explaining a configuration example in which a waterproof function is added to the electromagnetic induction pen of the first embodiment.

[0019] Figure 6 This is a diagram for explaining a configuration example in which a waterproof function is added to the electromagnetic induction pen according to the second embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the electromagnetic induction pen according to the present invention will be described with reference to the drawings.

[0021] [Examples of the appearance of an electromagnetic induction pen and a tablet-type information terminal]

[0022] Figure 1 This figure illustrates an example of the appearance of an electromagnetic induction pen 1 according to an embodiment and an example of the appearance of a tablet-type information terminal 2 using the electromagnetic induction pen 1 for information input. The electromagnetic induction pen 1 generally consists of two parts: a core 110 and a housing 120. The core 110 is equivalent to the tip of a fountain pen, etc. The housing 120 is the part held by the user. Furthermore, the electromagnetic induction pen 1 functions as a pen-shaped position indicator (coordinate indicator) used when inputting information into the tablet-type information terminal 2.

[0023] On the other hand, the tablet-type information terminal 2 has a structure in which a relatively large display screen 2D, such as a display device such as an LCD (Liquid Crystal Display), is exposed. A position detection device (input device) 200 having an electromagnetic induction sensor portion corresponding to the entire surface of the display screen 2D is mounted on the back of the display screen 2D, enabling detection of the indicated position regardless of the location on the display screen 2D. Furthermore, the sensor portion of the position detection device 200 is sometimes located on the back (back) of the display screen 2D, and sometimes on the front (front). In this example, the sensor portion is located on the back of the display screen 2D. Furthermore, a display device (such as an LCD) and an input device (position detection device 200) are connected to the interior of the housing of the tablet-type information terminal 2, along with an information processing device portion (not shown) that performs various information processing.

[0024] Thus, the tablet-type information terminal 2 is an information processing device with the position detection device 200 as the primary input device. Furthermore, a protective glass, for example, is provided on the display screen 2D, enabling pointing and input via the electromagnetic induction pen 1, using the display screen 2D as an operation surface. Furthermore, in the tablet-type information terminal 2, it is assumed that a position pointing operation is performed on the display screen 2D using the electromagnetic induction pen 1. In this case, based on the detection output from the sensor unit of the position detection device 200, which is located on the back of the display screen 2D, the processing unit (CPU (Central Processing Unit)) included in the position detection device 200 determines the indicated position on the display screen 2D. Information indicating the indicated position determined by the processing unit is supplied to the information processing unit mounted on the tablet-type information terminal 2, enabling corresponding processing.

[0025] Thus, the electromagnetic induction pen 1 of this embodiment and the position detection device 200 mounted on the tablet-type information terminal 2 are electromagnetic induction devices. In the electromagnetic induction method, the position detection device includes a sensor unit with multiple loop coils arranged in the X-axis direction and the Y-axis direction. A transmission period in which power is sequentially supplied to the multiple loop coils of the sensor unit to generate a magnetic field and a reception period in which power supply is stopped to receive an external magnetic field are alternately provided. The corresponding electromagnetic induction pen includes a resonant circuit composed of a coil and a capacitor. Based on the magnetic field from the sensor unit, a signal is generated by flowing current through the coil. This signal contains pen pressure information and is transmitted to the sensor unit. During the reception period, the position detection device receives this information through the sensor unit and detects the indicated position and pen pressure of the electromagnetic induction pen.

[0026] [Configuration Example of the Electromagnetic Induction Pen 1 of the First Embodiment]

[0027] Figure 2This is an external view of the connection portion between the core 110 and the housing 120 of the electromagnetic induction pen 1 according to the first embodiment ( Figure 2 (A)) and cross-sectional view ( Figure 2 (B)). Figure 2 As shown in the appearance diagram (A), the appearance of the electromagnetic induction pen 1 is roughly composed of two parts: the core 110 and the shell 120. Figure 2 As shown in FIG. 1B , the core 110 includes a nib 111 having a triangular cone shape and a rounded tip 111 a ; and a core rod 112 provided at a position aligned with the central axis of the nib 111 and extending away from the tip 111 a .

[0028] The housing 120 is on the pen tip side ( Figure 2 The left end side of (B) has an opening and is formed into a cylindrical shape, and an electronic pen function unit that realizes the function of the electronic pen is housed inside. Figure 2 As shown in (B), a coil portion 130 is provided on the side of the core body 110 in the housing 120. The coil 132 is formed by winding a coated conductive wire around the side of a ferrite core 131 having a through hole through which a core rod 112 of the core body 110 passes. A portion of the coil portion 130 extending from the front end of the ferrite core 131 on the pen tip side to the rear end thereof is provided from the pen tip side of the housing 120 ( Figure 2 The opening on the left end side of (B) is exposed to the outside (exposed).

[0029] The pen pressure detection unit 150 is connected to the rear end of the ferrite core 131 of the coil unit 130 via the core holder 140. The core holder 140 has a two-stage structure, a holding portion 141 having an inner diameter that is the same as or slightly shorter than the outer diameter of the ferrite core 131, and a connecting portion 142 having an outer diameter shorter than that of the holding portion 141. A through hole is provided in the connecting portion 142 of the core holder 140 for the core rod 112 of the core body 110 to pass through. Figure 2 As shown in FIG. 1B , the core holder 140 holds the ferrite core 131 by fitting the rear end portion of the ferrite core 131 with the holding portion 141 . Meanwhile, the core holder 140 holds the front end portion of the writing pressure detection unit housing 151 with the connecting portion 142 fitted therein.

[0030] like Figure 2 As shown in FIG. 1B , the pen pressure detection unit 150 houses a pressing member 152 within a cylindrical pen pressure detection unit housing 151 that holds the rear end of the core rod 112 of the core body 110 . The pressing member 152 is formed of an elastic material such as rubber, and allows the core rod 112 of the core body 110 to be inserted and removed. Once inserted, the core rod 112 is held in place to prevent it from easily falling out.

[0031] The rear end of the pressure detection unit housing 151 is also open and sealed with a conductive rubber 153. As described below, the conductive rubber 153 serves as one electrode of a variable capacitor. Although not shown, an annular spacer is provided on the side of the conductive rubber 153 opposite the pressure detection unit housing 151, and a dielectric 154 is provided across this spacer. Consequently, a gap SP is provided between the conductive rubber 153 and the dielectric 154. Furthermore, another electrode 155 is provided on the surface of the dielectric 154 opposite the conductive rubber 153.

[0032] Thus, the conductive rubber 153 and the electrode 155 are arranged so as to face each other with the dielectric 154 interposed therebetween, forming a capacitor. Furthermore, since the gap SP is provided between the conductive rubber 153 and the dielectric 154 as described above, the capacitor functions as a variable capacitor whose capacitance changes depending on the proximity of the conductive rubber 153 to the dielectric 154.

[0033] Furthermore, the front end portion 111 of the core 110 has a recessed portion that is recessed from the side (bottom side) opposite to the front end 111a toward the front end 111a. Therefore, if the core 110 is mounted on the housing 120 equipped with the electronic pen function unit, Figure 2 As shown in (B), the front end of the ferrite core 131 constituting the electronic pen function unit enters the recess of the front end 111 of the core body 110. In this case, as shown in FIG. Figure 2 As shown in FIG. 1B , the recess formed in the front end portion 111 of the core body 110 includes a wall portion 113 of an inner wall 111 n facing the pen tip side columnar side surface 131 a of the ferrite core 131 along a predetermined length in the axial direction of the housing 120 .

[0034] In addition, if Figure 2 As shown in (B), the opening portion of the pen tip side of the housing 120 is formed with a recess toward the rear end side, and the rear end side of the front end portion 111 of the core 110 enters the recess. Figure 2 As shown in (B), the wall portion 113 of the front end portion 111 of the core body 110 is sandwiched between the ferrite core 131 and the housing 120 along a predetermined length in the axial direction of the housing 120. In other words, the wall portion 113 of the front end portion 111 of the core body 110 is sandwiched between the columnar side surface 131a of the ferrite core 131 and the inner wall surface 120a of the front end portion of the housing 120.

[0035] In this case, if Figure 2As shown in (B), a gap SP1 is provided between the recessed portion of the front end portion 111 of the core body 110 and the tip-side tip end portion of the ferrite core 131. Furthermore, a gap SP2 is provided between the rear end surface of the wall portion 113 of the front end portion 111 of the core body 110 and the front end surface within the recessed portion on the tip side of the housing 120. Thus, when writing pressure is applied to the core body 110, the core body 110 is pressed toward the housing 120, and the core rod 112 of the core body 110 presses the conductive rubber 153 toward the dielectric 154 via the pressing member 152 of the writing pressure detection unit 150. Furthermore, when the writing pressure applied to the core body 110 is released, the core body 110 is pushed back by the elastic force of the conductive rubber 153 and the like. Therefore, the state of the conductive rubber 153 close to the dielectric 154 changes according to the writing pressure applied to the core 110 , and the capacitance of the writing pressure detection unit 150 changes. Therefore, the writing pressure applied to the core 110 can be accurately detected based on the changing capacitance.

[0036] Furthermore, the rear end surface of the pressure detection unit housing 151 of the pressure detection unit 150 is pressed against the front end surface of the cylindrical inner housing 190. A substrate retaining member 161 is provided on the electrode 155 side of the pressure detection unit 150 to press the electrode 155 toward the dielectric 154. The substrate retaining member 161 is retained within the inner housing 190 by a cylindrical fixing member 162 so as to prevent movement in a direction intersecting the axis. Furthermore, the circuit substrate 170 is held within the inner housing 190 by the substrate retaining member 161 and the fixing member 162. The circuit substrate 170 is formed into an electronic circuit using various circuit elements, such as an integrated circuit (IC) constituting the control unit and a plurality of capacitors.

[0037] The circuit substrate 170 is housed within the substrate protection tube 180, with the end of the substrate protection tube 180 on the core body 110 side contacting the end of the fixing member 162. The tube is then closed by a cover (not shown) that contacts the rear end of the substrate protection tube 180 from the rear end of the inner housing 190. This secures the positions of the pen pressure detection unit 150, substrate retaining member 161, fixing member 162, circuit substrate 170, and substrate protection tube 180 within the inner housing 190. Furthermore, the coil unit 130 and the pen pressure detection unit 150 are connected via the core holder 140. Furthermore, a predetermined cover presses the inner housing 190 from the rear end of the housing 120 toward the core body 110, thereby restricting its position.

[0038] Although not shown, both ends of the coil 132 disposed around the ferrite core 131 are connected to the electronic circuit formed on the circuit substrate 170. As described above, the electronic circuit formed on the circuit substrate 170 is constructed using a plurality of circuit elements such as capacitors, with the coil 132 and the capacitors on the circuit substrate 170 forming a resonant circuit. Furthermore, the conductive rubber 153 and electrodes 155 of the pen pressure detection unit 150 are also connected to the electronic circuit of the circuit substrate 170 via conductive wires. Thus, the electronic pen functional unit, primarily composed of the coil 130, the pen pressure detection unit 150, and the circuit substrate 170, is formed within the housing 120.

[0039] Therefore, the signal transmitted from the electromagnetic induction position detection device 200 of the tablet-type information terminal 2 is received by the resonant circuit formed by the coil 132 and capacitor of the electromagnetic induction pen 1. Furthermore, a signal corresponding to the received signal is generated in this resonant circuit of the electromagnetic induction pen 1 and transmitted to the position detection device 200. At this time, the phase of the transmitted signal is adjusted according to the writing pressure detected by the writing pressure detection unit 150, and the writing pressure applied to the core 110 of the electromagnetic induction pen 1 is also notified to the position detection device 200.

[0040] The electromagnetic induction pen 1 is laid down (flat) so that the side surface of the front end portion 111 of the core 110 contacts the operation surface on the display screen 2D of the tablet-type information terminal 2 to perform instruction input. Figure 2 As described in (A) and (B), the front end portion 111 of the core 110 is a triangular pyramid (conical shape), so the side surface of the front end portion 111 is inclined. Figure 2 In (A), the pen pressure is applied as shown by the solid arrow f. Figure 2 As indicated by the dotted arrow in (A), the component fa in the direction intersecting the axis of the electromagnetic induction pen 1 and the component fb in the direction along the axis of the electromagnetic induction pen 1 are included.

[0041] Therefore, when a writing pressure f is applied to the side surface of the tip 111 of the core body 110, a component fb thereof is applied to the core rod 112 of the core body 110 and transmitted to the writing pressure detection unit 150, thereby enabling detection of the writing pressure. By being able to detect both the indicated position and the writing pressure, it is possible to perform pointing input on the tablet-type information terminal 2. For example, the electromagnetic induction pen 1 can be used to perform pointing input on the tablet-type information terminal 2, such as by tilting a pencil to create shading.

[0042] That is, the magnetic field (magnetic field) generated in the electromagnetic induction pen 1 reaches the position detection sensor of the tablet-type information terminal 2, and forms an appropriate magnetic field distribution on the position detection sensor, which can identify the indicated position and pen pressure. Therefore, when the electromagnetic induction pen 1 is used upright in the manner of writing text, it is possible to form a magnetic field distribution in a narrow range on the position detection sensor, and perform line drawing input. In addition, when the electromagnetic induction pen 1 is used flat in the manner of painting, a magnetic field distribution is formed in a relatively wide range on the position detection sensor, and painting input can be performed. Moreover, when using Figure 2 In the case of the electromagnetic induction pen 1 according to the first embodiment, there is no need to provide the housing 120 with a fitting groove or the like into which a portion of the core body fits, and therefore the strength of the housing 120 is not reduced.

[0043] Furthermore, as mentioned above, the pen tip-side portion of ferrite core 131 protrudes from the pen tip-side opening of housing 120. Therefore, when core body 110 is removed, the pen tip-side portion of ferrite core 131 is exposed to the outside, potentially causing the user to pull it out. Therefore, it is preferable to bond the rear end portion of ferrite core 131 to the retaining portion 141 of core holder 140 to prevent removal.

[0044] Core holder 140 is prevented from moving toward the pen tip by, for example, its front end engaging with a protrusion on the inner wall of housing 120. Furthermore, it is also restrained from moving toward the rear end by the pressure detector housing 151 and inner housing 190. In other words, core holder 140 is fixed within housing 120, preventing easy removal of ferrite core 131. Furthermore, core holder 140 is made of a resin material, making it easy to form and electrically safe from other components.

[0045] In addition, if Figure 2 As shown in (B), in the first embodiment of the electromagnetic induction pen 1, the tip-side end of the recessed portion of the tip end 111 of the core body 110 and the tip-side tip end of the ferrite core 131 have corresponding stepped shapes that fit together. This ensures that when writing pressure is applied to the core body 110, the tip-side end of the recessed portion of the tip end 111 of the core body 110 and the tip-side tip end of the ferrite core 131 fit together, preventing play in a direction intersecting the axial direction.

[0046] [Configuration Example of the Electromagnetic Induction Pen 3 According to the Second Embodiment]

[0047] In use Figure 2In the case of the electromagnetic induction pen 1 of the first embodiment described above, the tip 111 of the core 110 is small, so when the electromagnetic induction pen 1 is laid down for use, it is considered that the usability may be deteriorated. Therefore, in the case of the electromagnetic induction pen 3 of the second embodiment, the tip 311 of the core 310 is configured to be larger than the tip 111 of the core 110 of the electromagnetic induction pen 1 of the first embodiment. Therefore, the electromagnetic induction pen 3 of the second embodiment is also used Figure 1 The electromagnetic induction pen 1 described above can also be used as a position indicator for the tablet-type information terminal 2 .

[0048] In the electromagnetic induction pen 3 of the second embodiment described below, the structure of the core 310 and the shell 320 are different from those of the electromagnetic induction pen 1 of the first embodiment. However, the structure of the electronic pen body other than these is substantially the same as that of the electromagnetic induction pen 1 of the first embodiment. Figure 3 In the electromagnetic induction pen 3 of the second embodiment shown, components having the same configuration as those of the electromagnetic induction pen 1 of the first embodiment are denoted by the same reference numerals, and detailed description of these components is omitted.

[0049] Figure 3 This is an external view of the connection portion between the core 310 and the housing 320 of the electromagnetic induction pen 3 according to the second embodiment ( Figure 3 (A)) and cross-sectional view ( Figure 3 (B)). Figure 3 As shown in the appearance diagram (A), the appearance of the electromagnetic induction pen 3 is roughly composed of two parts: the core 310 and the shell 320. Figure 3 As shown in (B), the core body 310 is composed of a front end portion (nib) 311 having a triangular pyramid shape with a rounded front end 111a and a core rod 312 provided at a position aligned with the central axis of the front end portion 311 and extending in a direction away from the front end 311a. Figure 3 and Figure 2 It can be seen that the front end portion 311 of the core body 310 of the second embodiment is formed larger on the rear end side than the front end portion 111 of the core body 110 of the first embodiment.

[0050] Housing 320 Figure 3 The left end of (B) is formed into an opening and is cylindrical, and an electronic pen function unit that realizes the function of an electronic pen is housed inside. Figure 3 As shown in FIG. 3B , a mounting portion 320a is provided on the pen tip side of the housing 320, where its outer diameter is shortened and the front end 311 of the core body 310 is mounted. The end surface of the mounting portion 320a on the pen tip side forms an opening, and a portion of the ferrite core 131 extending from the front end toward the rear end protrudes from this opening.

[0051] Thus, in the electromagnetic induction pen 3 of the second embodiment, the ferrite core 131 protrudes significantly from the opening on the pen tip side of the housing 320. Therefore, when the core 310 is not attached, the tip of the ferrite core 131 may be caught by the claws or bitten by the teeth and pulled out. Figure 3 As shown in FIG. 1 (B), the side surface of the rear end portion of the ferrite core 131 and the inner wall surface of the holding portion of the core holder 140 are bonded together by an adhesive Ad.

[0052] Furthermore, the front end portion 311 of the core 310 has a recessed portion that is recessed from the side (bottom side) opposite to the front end 311a toward the front end 311a. Therefore, if the core 310 is mounted on the housing 320 equipped with the electronic pen function unit, Figure 3 As shown in (B), the front end of the ferrite core 131 constituting the electronic pen function unit and the mounting portion 320a of the housing 320 enter the recess of the front end 311 of the core 310. In this case, as shown in FIG. Figure 3 As shown in (B), the concave portion formed at the front end portion 311 of the core body 310 is a wall portion having a first inner wall 311n facing along a predetermined length in the axial direction of the housing 120 on the columnar side 131a on the pen tip side of the ferrite core 131. Figure 3 As shown in (B), the side surface 320g of the mounting portion 320a of the housing 320 (the surface of the outer diameter of the opening portion of the housing 320) and the second inner wall 311m on the opening side of the front end portion 311 of the core 310 are arranged to face each other along a predetermined length in the axial direction of the housing 320.

[0053] In this case, if Figure 3 As shown in (B), a gap SPa is provided between the tip-side end of the recessed portion of the front end portion 311 of the core body 310 and the tip-side tip end of the ferrite core 131. Furthermore, a gap SPb is provided between the end surface of the middle portion of the recessed portion of the front end portion 311 of the core body 310 and the tip-side end surface of the mounting portion 320a of the housing 320. Furthermore, a gap SPc is provided between the rear end surface of the front end portion 311 of the core body 310 and the end surface extending outward from the rear end portion of the mounting portion 320a of the housing 320.

[0054] Thus, when writing pressure is applied to the core 310, the core 310 is pressed into the housing 320, and the core rod 312 of the core 310 presses the conductive rubber 153 into the dielectric 154 via the pressing member 152 of the writing pressure detection unit 150. Furthermore, when the writing pressure applied to the core 310 is released, the core 310 is pushed back by the elastic force of the conductive rubber 153 and the like. Therefore, the state of the conductive rubber 153 approaching the dielectric 154 changes according to the writing pressure applied to the core 310, and the electrostatic capacitance of the writing pressure detection unit 150 changes, so that the writing pressure applied to the core 310 can be accurately detected based on this changing electrostatic capacitance.

[0055] In the case of the electromagnetic induction pen 3 of the second embodiment, the tip 311 of the core 310 is larger than that of the Figure 2 The electromagnetic induction pen 1 of the first embodiment described above has a larger tip 111 of the core 110. Therefore, compared to the electromagnetic induction pen 1 of the first embodiment, when the electromagnetic induction pen 3 is used flat for painting, a magnetic field distribution can be formed over a wider range on the position detection sensor, enabling better drawing input for painting.

[0056] Specifically, in the electromagnetic induction pen 3 of the second embodiment, the inner wall surface of the recessed portion of the tip 311 of the core body 310 also faces the tip of the ferrite core 131 and the side surface of the mounting portion 320a of the housing 320. This prevents the core body 310 from bending even when used flat, allowing it to slide appropriately in the axial direction, allowing for appropriate application of writing pressure to the writing pressure detection unit 150.

[0057] Moreover, when using Figure 3 In the electromagnetic induction pen 3 of the second embodiment described above, there is no need for a fitting groove or the like in the housing 320 for partially fitting the core body, thereby preventing a reduction in the strength of the housing 320. Furthermore, the distal end of the ferrite core 131 of the coil unit 130 protrudes (is exposed) from the housing 120, thereby enabling the formation of a desired magnetic field distribution within the position detection sensor. Furthermore, even if the distal end of the ferrite core 131 protrudes from the housing 120, the ferrite core 131 is prevented from being removed from the housing 120 by, for example, adhesively securing the rear end of the ferrite core 131 to the core holder 140.

[0058] In addition, if Figure 3As shown in (B), in the electromagnetic induction pen 3 of the second embodiment, the tip-side end of the recessed portion of the tip 311 of the core body 310 and the tip-side tip end of the ferrite core 131 have corresponding stepped shapes that fit together. This ensures that when writing pressure is applied to the core body 310, the tip-side end of the recessed portion of the tip 311 of the core body 310 and the tip-side tip end of the ferrite core 131 fit together, preventing play in a direction intersecting the axial direction.

[0059] In addition, regarding the use Figure 3 The electromagnetic induction pen 3 described above can appropriately determine the positional relationship between the ferrite core 131 around which the coil 132 is wound and the core body 310 , thereby forming a desired magnetic field distribution on the position detection sensor. Figure 4 : is a diagram for explaining the dimensions of each part on the pen tip side of the electromagnetic induction pen 3 according to the second embodiment. Figure 4 As shown, the length of the core body 310 from the front end 311a in the axial direction to the tip of the core rod 312 (the base of the core rod 312) is R1. Furthermore, the length of the portion where the cylindrical side surface 131a on the pen tip side of the ferrite core 131 and the first inner wall 311n of the front end 311 of the core body 310 face each other is R2. Furthermore, the depth of the recessed portion of the front end 311 of the core body 310 is R3, and the length of the core rod 312 is R4.

[0060] In this case, if Figure 4 As shown in (B), by setting length R1 to 3 mm or greater, length R2 to 1 mm or greater, depth R3 to 5 mm or greater, and length R4 to 20 mm or greater, an electromagnetic induction pen 3 capable of good writing input can be realized. That is, the electromagnetic induction pen 3 of the second embodiment can be defined as follows.

[0061] That is, the electromagnetic induction pen 3 of the second embodiment can be said to be the following electromagnetic induction pen:

[0062] include:

[0063] (1) A housing having an opening at one end;

[0064] (2) a pen pressure detection portion fixed to the housing;

[0065] (3) a columnar magnetic body having a through hole and a coil wound thereon; and

[0066] (4) a core for transmitting force to the pen pressure detection unit,

[0067] The core comprises:

[0068] (5) A tip portion having a distance of more than 3 mm from the front end to the root in the axial direction;

[0069] (6) a core rod having a length of 20 mm or more from the base of the tip portion in the axial direction and passing through the through hole; and

[0070] (7) The covering portion covers a portion of the magnetic body at a distance of 1 mm or more, and covers the core rod at a distance of 5 mm or more from the root in the axial direction.

[0071] In addition, the covering portion of the core shown in (7) above is equivalent to Figure 3 The inner wall of the recessed portion of the tip 311 of the electromagnetic induction pen 3 shown in FIG. Specifically, the core covering portion is formed by a first inner wall 311n facing the tip 131a of the ferrite core 131 and a second inner wall 311m facing the side surface of the mounting portion 320a of the housing 320.

[0072] [Structure with additional waterproof function]

[0073] Figure 5 1 is a diagram for explaining a configuration example in which a waterproof function is added to the electromagnetic induction pen 1 of the first embodiment. Figure 5 As shown in (A), the appearance of the electromagnetic induction pen 1A of this example is similar to Figure 2 The electromagnetic induction pen 1 of the first embodiment shown in FIG. 120A is similar to the electromagnetic induction pen 1 of the first embodiment shown in FIG. However, some changes are made to the housing 120A, and a packing is provided for waterproofing.

[0074] observe Figure 2 As can be seen from (B), an extension extending inward is formed in the opening portion of the pen tip side of the housing 120. Figure 5 As shown in FIG (B), an annular seal WP1 is provided at the tip-side opening of housing 120A. This seal fills (blocks) the gap between the inner wall of the opening of housing 120A and the side surface of ferrite core 131. This prevents moisture from flowing from the tip-side opening of housing 120A into coil 132.

[0075] In addition, an annular seal WP2 is also provided between the side surface of the rear end portion of the ferrite core 131 and the inner wall surface of the retaining portion 141 of the core holder 140. This prevents moisture flowing in from the through hole of the ferrite core 131 from flowing into the coil 132 side. In addition, the seal WP2 can also be implemented by using an adhesive as an adhesive layer. That is, by bonding the side surface of the rear end portion of the ferrite core 131 to the inner wall surface of the retaining portion 141 of the core holder 140 using an adhesive, it is possible to prevent moisture from flowing in and prevent the ferrite core 131 from being pulled out. In addition, a gasket WP3 is also provided between the core holder 140 and the pen pressure detection unit housing 151. This prevents moisture from flowing further into the rear section.

[0076] Figure 6 1 is a diagram for explaining a configuration example in which a waterproof function is added to the electromagnetic induction pen 3 of the second embodiment. Figure 6 As shown in (A), the appearance of the electromagnetic induction pen 3A of this example is similar to Figure 3 The electromagnetic induction pen 3 of the first embodiment shown in FIG. 320A is similar to the electromagnetic induction pen 3 of the first embodiment shown in FIG. 320A. However, some changes are made to the housing 320A, and a packing is provided for waterproofing.

[0077] observe Figure 3 As can be seen from (B), an extension extending inward is formed in the opening portion of the pen tip side of the mounting portion 320a of the housing 320. Figure 6 As shown in FIG. 3B , an annular seal WPa is provided to fill (block) the gap between the inner wall surface of the opening of the mounting portion 320a of the housing 320A and the side surface of the ferrite core 131. This prevents moisture from flowing into the coil 132 from the opening on the pen tip side of the housing 320A.

[0078] In addition, an annular gasket WPb is also provided between the side surface of the rear end portion of the ferrite core 131 and the inner wall surface of the retaining portion 141 of the core holder 140. This prevents moisture flowing in from the through hole of the ferrite core 131 from flowing into the coil 132 side. In addition, the seal WPb can also be implemented by using an adhesive as an adhesive layer. That is, by bonding the side surface of the rear end portion of the ferrite core 131 to the inner wall surface of the retaining portion 141 of the core holder 140 using an adhesive, it is possible to prevent moisture from flowing in and prevent the ferrite core 131 from being pulled out. In addition, a gasket WPc is also provided between the core holder 140 and the pen pressure detection unit housing 151. This prevents moisture from flowing further into the rear section.

[0079] Furthermore, each of the seals WP1, WP2, WP3, WPa, WPb, and WPc can be made of rubber, resin, or polyurethane such as PORON (registered trademark). Furthermore, when seals WP2 and WPb are implemented as adhesive layers using an adhesive, various adhesive materials can be used as long as they can bond the substantially thin and small ferrite core 131 to the holding portion 141 of the core holder 140 with sufficient strength.

[0080] [Effects of the embodiment]

[0081] According to the electromagnetic induction pen 1, 3 of the above embodiment, when used in a flat manner for painting, a magnetic field distribution can be formed in a relatively wide range on the position detection sensor to perform painting drawing input. Figure 2In the case of the electromagnetic induction pen 1 of the first embodiment described above, there is no need to provide a fitting groove for partially fitting the core body in the housing 120, thereby preventing a decrease in the strength of the housing 120. In addition, the ferrite core 131 can be prevented from being pulled out, and a waterproof function can be added.

[0082] Description of Reference Numerals

[0083] 1. 1A…Electromagnetic induction pen, 110…Core, 111…Front end, 111a…Front end, 112…Core rod, 111n…Inner wall, 113…Wall, 120…Casing, 120a…Inner wall, SP1, SP2…Gap, WP1, WP2, WP3…Pad, 3. 3A…Electromagnetic induction pen, 310…Core, 311…Front end, 311a…Front end, 311n…First inner wall, 31 1m…second inner wall, 312…core rod, 320…shell, 320a…mounting portion, 320g…side, SPa, SPb, SPc…gap, 130…coil portion, 131…ferrite core, 131a…columnar side, 132…coil, 140…core retaining frame, 141…retaining portion, 142…connecting portion, 150…pen pressure detection portion, Ad…adhesive, WPa, WPb, WPc…pad.

Claims

1. An electromagnetic induction pen, comprising: a housing having an opening at one end; a pen pressure detection unit, fixed to the housing; A columnar magnetic body having a coil wound thereon and a through hole; and The core body includes a core rod that passes through the through hole to transmit force to the writing pressure detection unit, and a wall portion having an inner wall that faces the columnar side surface of the magnetic body along a predetermined length in the axial direction of the shell. The electromagnetic induction pen uses the magnetic body to form a magnetic field.

2. The electromagnetic induction pen according to claim 1, The outer wall of the wall portion has a diameter smaller than the diameter of the opening portion, The wall portion is sandwiched between the magnetic body and the housing along a predetermined length in the axial direction.

3. The electromagnetic induction pen according to claim 1, A portion of the magnetic body is exposed from the opening when the core is removed.

4. The electromagnetic induction pen according to claim 3, The magnetic body is bonded to a magnetic body holder, and the magnetic body holder is fixed to the housing.

5. The electromagnetic induction pen according to claim 4, The magnetic holder is formed of a resin material.

6. The electromagnetic induction pen according to claim 1, comprising: a first waterproof member provided between an inner wall of the housing near the opening and the columnar side surface of the magnetic body; and The second waterproof member includes a magnetic body holder that holds the rear end portion of the magnetic body and is provided between a side surface of the rear end portion of the magnetic body and an inner wall surface of the magnetic body holder.

7. An electromagnetic induction pen, comprising: a housing having an opening at one end; a core body having a front end portion and a core rod; a magnetic body formed into a columnar shape so as to be wound with a coil, having a hole through which the core rod passes, and provided at a position where the front end side is exposed from the opening when the core body is removed; and The magnetic body holder is fixed to the housing and has a fixing portion for fixing the rear end side of the magnetic body so that the magnetic body does not fall out of the opening.

8. The electromagnetic induction pen according to claim 7, The magnetic holder is formed of a resin material.

9. The electromagnetic induction pen according to claim 7, The fixing portion is an adhesive layer formed of an adhesive material.

10. The electromagnetic induction pen according to claim 7, The front end portion of the core body includes a wall portion having an inner wall facing a side surface of the magnetic body along a predetermined length in the axial direction of the housing.

11. The electromagnetic induction pen according to claim 10, Furthermore, the outer diameter surface of the opening portion of the housing and the inner wall surface of the core face each other at a second distance in the axial direction.

12. The electromagnetic induction pen according to claim 7, comprising: a first waterproof member provided between an inner wall of the housing near the opening and a side surface on the front end side of the magnetic body; and The second waterproof member is provided between the side surface of the rear end portion of the magnetic body and the inner wall surface of the magnetic body holder.

13. An electromagnetic induction pen, comprising: a housing having an opening at one end; a pen pressure detection unit, fixed to the housing; A columnar magnetic body having a coil wound thereon and a through hole; and The core transmits force to the pen pressure detection part, The core comprises: The tip portion has a distance of more than 3 mm from the front end to the root in the axial direction; a core rod having a length of 20 mm or more in the axial direction from the base of the tip portion and passing through the through hole; and The covering portion covers a portion of the magnetic body at a distance of 1 mm or more, and covers the core rod at a distance of 5 mm or more from the root in the axial direction.

14. The electromagnetic induction pen according to claim 13, The covering portion includes an inner surface in contact with the magnetic body.

15. The electromagnetic induction pen according to claim 13, The cover portion includes an inner surface in contact with a portion of the housing.

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