Electronic pen

Abstract

Provided is a knocking electronic pen, wherein ease of use in a case where a position designation part is provided on a knocking-operation-part side is improved.　The present invention comprises a first position designation part that is disposed at one axial end within a cylindrical pen housing, a second position designation part that is disposed at the other axial end, and a knock cam mechanism part that is driven by a load applied from the other-axial-end side. The first position designation part is disposed such that the distal end can be advanced through or retracted from an opening in the pen housing by the knock cam mechanism part. The second position designation part is disposed in a state in which the distal end is on the other-axial-end side. The present invention also comprises an elastic member for enabling the distal end of the first position designation part to be advanced through or retracted from a first opening by the knock cam mechanism part when pressure greater than the pressure applied to the distal end is applied during use of the second position designation part.

Description

Electronic pen

[0001] The present invention relates to an electronic pen used together with a position detection device, which has a mechanism for extending and retracting the pen tip by a knock.

[0002] Due to the recent trend toward miniaturization, there is a growing demand for smaller portable electronic devices as well. Electronic pens are now being used together with position detection sensors mounted on these small electronic devices, and thinner electronic pens are being demanded.

[0003] Furthermore, electronic pens have recently come to be seen as an extension of stationery, and there is a demand for their internal configuration to be modularized so that they can be handled in the same way as ballpoint pen refills (refills or cartridges).In the following, in this specification, an electronic pen cartridge will be referred to as an electronic pen cartridge, which is an integrated modularization of the components of the position indication section inside the pen housing of an electronic pen, configured to be replaceable like a ballpoint pen refill.

[0004] The applicant has already proposed a knock-type electronic pen in which the electronic pen cartridge is configured to be handled in the same way as a ballpoint pen refill, and the housing of a stationery knock-type ballpoint pen can be used as the pen housing of the electronic pen (see, for example, Patent Document 1 (Patent Publication No. 5959038)).

[0005] Patent No. 5959038

[0006] Incidentally, there is also provided an electronic pen equipped with an electronic eraser functional unit having a configuration similar to that of the position indication unit for handwriting input, for erasing information handwritten and input on a position detection sensor by the position indication unit of the electronic pen. In this case, the position indication unit for handwriting input is arranged at one end of the axial direction of the cylindrical pen housing, and the position indication unit constituting the electronic eraser functional unit is arranged at the other end of the axial direction of the cylindrical pen housing.

[0007] In the case of the above-mentioned knock-type electronic pen, it is conceivable that the position indicating section constituting the electronic eraser function section is provided on the side where the knock operation is performed.

[0008] However, when the knock operation part of the knock cam mechanism is pressed down to cause the position indicating part for handwriting input to protrude from one opening of the housing, the pressure (load) applied to press down has not conventionally been set to be large in order to make the knock operation relatively easy. Therefore, when the knock operation part is brought into contact with the input surface of the position detection sensor to apply pressure in order to operate the position indicating part that constitutes the electronic eraser function part, there is a risk that the knock mechanism will operate, which poses a problem of poor usability of the electronic eraser function part.

[0009] The same problem occurs when a position indicator for handwriting input is provided on the knock section side, instead of the position indicator constituting the electronic eraser function section.

[0010] SUMMARY OF THE INVENTION An object of the present invention is to provide a position indicator that can solve the above problems.

[0011] In order to solve the above problem, an electronic pen is provided, comprising: a cylindrical pen housing; a first position indicating unit disposed at one axial end of the pen housing; a second position indicating unit disposed at the other axial end of the pen housing; and a knock cam mechanism unit driven by an axial load applied from the other axial end, wherein the first position indicating unit is disposed such that a tip side that indicates a position can be protruded and retracted from an opening at the one axial end of the pen housing by the knock cam mechanism; the second position indicating unit is disposed such that its tip side that indicates a position is at the other axial end, and the electronic pen is provided with an elastic member that causes the tip side of the first position indicating unit to protrude and retract from the opening by the knock cam mechanism when a pressure greater than a pressure applied to the tip side of the second position indicating unit when the second position indicating unit is used is applied from the other axial end.

[0012] In the electronic pen having the above-described configuration, the knock cam mechanism is configured to include an elastic member that causes the tip side of the first position indicating unit to protrude and retract from the first opening of the pen housing when a pressure greater than the pressure applied to the tip side that indicates the position is applied from the other end side in the axial direction of the pen housing during use of the second position indicating unit.

[0013] Therefore, with an electronic pen having the above-described configuration, when the second position indication unit is used, the range of pressure applied to its tip side prevents the knock cam mechanism from causing the tip side of the first position indication unit to appear and disappear from the first opening, making the second position indication unit easy to use.

[0014] FIG. 2 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 3 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 4 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 5 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 6 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 7 is an exploded perspective view illustrating an example of the configuration of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 8 is an exploded perspective view illustrating ... FIG. 1 is a diagram for explaining a state in which the pen tip side of the first position indicator is housed within the pen housing in an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 2 is a diagram for explaining a state in which the pen tip side of the first position indicator is extended from an opening of the pen housing in an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 3 is a diagram for explaining the movement of the pen tip side during a knock operation of an example of a conventional knock-type electronic pen. FIG. 4 is a diagram for explaining the movement of a knock cam mechanism and the movement of the pen tip side during a knock operation of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 5 is a diagram for explaining the movement of a knock cam mechanism and the movement of the pen tip side during a knock operation of an electronic pen body module constituting an embodiment of the electronic pen according to the present invention. FIG. 6 is a diagram for explaining another example of the main parts of the first position indicator in an embodiment of the electronic pen according to the present invention.

[0015] Hereinafter, an embodiment of an electronic pen according to the present invention will be described with reference to the drawings.

[0016] 1 is a diagram illustrating an overview of an electronic pen 1 according to an embodiment. In this example, the electronic pen 1 has a first position indicator that includes a first electronic pen cartridge for handwriting input, and a second position indicator that includes a second electronic pen cartridge to which an electronic eraser function is assigned. In this embodiment, both the first position indicator and the second position indicator are of the electromagnetic induction type.

[0017] In the electronic pen 1 of this embodiment, as will be described below, a first electronic pen cartridge for writing input as an example of a first position indicator and a second electronic pen cartridge assigned with an electronic eraser function as an example of a second position indicator are arranged axially within the hollow portion of the cylindrical pen housing 2. In this case, the tip side of the first electronic pen cartridge is at one end side of the pen housing 2 in the axial direction, and the tip side of the second electronic pen cartridge is at the other end side of the pen housing 2 in the axial direction.

[0018] In the following description, for convenience, one end of the pen housing 2 in the axial direction will be referred to as the pen tip side, and the other end as the rear side. Furthermore, the first electronic pen cartridge for writing input, which is an example of a first position indication unit, will be referred to as the writing input cartridge, and the second electronic pen cartridge, which is an example of a second position indication unit and has an electronic eraser function assigned to it, will be referred to as the erasing cartridge.

[0019] In the electronic pen 1 of this embodiment, a writing input pen cartridge and an eraser cartridge are coupled together in the axial direction within the knock cam mechanism, and the writing input cartridge and the eraser cartridge are moved in the axial direction in response to a knock operation that drives the knock cam mechanism, so that the tip side of the writing input cartridge appears and disappears from an opening 2a on the pen tip side of the pen housing 2. Note that the portion Nk of the knock cam mechanism that receives the knock operation (hereinafter referred to as the knock operation portion Nk) is in a state that protrudes to the outside from an opening 2b on the rear end side of the pen housing 2. The tip side of the eraser cartridge is configured to be located within the housing of this knock operation portion Nk.

[0020] Fig. 1(A) is a perspective view illustrating the appearance of the electronic pen 1 of this embodiment. The pen housing 2 of the electronic pen 1 of this embodiment is made of, for example, resin, and is configured by axially connecting a pen tip side housing section 21 that houses the pen tip side portion of the handwriting input cartridge, and a rear end side housing section 22 (see Fig. 1(C)) that houses the rear end side portion of the handwriting input cartridge and a section including the eraser cartridge and knock cam mechanism section. Fig. 1(A) shows the rear end side housing section 22 as being made of a transparent material, allowing the interior to be seen.

[0021] In this embodiment of the electronic pen 1, the main body components of the electronic pen, including the writing input cartridge, the erasing cartridge, and the knock cam mechanism, are housed in a single modularized component. Figure 1(B) shows the modularized component 3 in this embodiment, which includes a pen tip side housing 21. Hereinafter, this modularized component 3 will be referred to as the electronic pen main body module 3.

[0022] The pen tip side housing 21 is configured as a cylindrical body, with one side in the axial direction being a tapered section 2Aa that is gradually tapered, and the other side in the axial direction being a cylindrical section 21b whose outer diameter Ra is equal to or slightly smaller than the inner diameter of the rear end side housing 22. The opening at the tapered tip side of the tapered section 2Aa is the opening 2a of the pen housing 2 that allows the tip side of the writing input cartridge to protrude and retract.

[0023] In this embodiment, an electronic pen main body component 4, which is constructed by integrally combining a writing input cartridge, an erasing cartridge, and a knock cam mechanism, is connected to the cylindrical portion 21b side of the pen tip side housing portion 21, thereby forming an electronic pen main body module 3.

[0024] 1C, the inner diameter of the connecting side with the cylindrical portion 21b of the pen tip side housing 21 is equal to or slightly larger than the outer diameter Ra of the cylindrical portion 21b of the pen tip side housing 21. The inner diameter Rb of the rear end side of the rear end side housing 22 is larger than the diameter Ra.

[0025] 1(B) and 1(C), the electronic pen body module 3 is inserted into the hollow portion of the rear-end housing 22 from the electronic pen body forming portion 4 side and pushed into the cylindrical portion 21b of the pen tip housing 21, thereby joining the tip housing 21 and the rear housing 22 of the electronic pen body module 3. In this manner, the electronic pen 1 shown in Fig. 1(A) is formed. At this time, as shown in Fig. 1(A), the knock operation portion Nk at the end on the rear side of the electronic pen body module 3 protrudes to the outside from the rear opening of the rear housing 22, which is the rear opening 2b of the pen housing 2.

[0026] In this embodiment, ring-shaped recessed grooves 21c and 21d are formed in the cylindrical portion 21b of the pen tip side housing 21, and ring-shaped protrusions 22a and 22b are formed on the inner wall of the rear end side housing 22 at positions corresponding to the recessed grooves 21c and 21d. As a result, when the cylindrical portion 21b of the pen tip side housing 21 of the electronic pen main body module 3 is inserted into the hollow portion of the rear end side housing 22 and coupled, the ring-shaped recessed grooves 21c and 21d and the ring-shaped protrusions 22a and 22b fit together, locking the pen tip side housing 21 and the rear end side housing 22 in a coupled state. However, the electronic pen main body module 3 and the rear end side housing 22 can be separated by pulling the pen tip side housing 21 and the rear end side housing 22 in directions separating them from each other.

[0027] 1C is one example, and the outer shape of the rear-end side housing 22 may be any shape as long as it can be pressed into and coupled to the cylindrical portion 21b of the pen tip side housing 21 of the electronic pen main body module 3, and various shapes such as a shape that is easy for a user to grip can be used. In other words, the rear-end side housing 22 can be configured in any shape as a cosmetic case as long as it is configured to accommodate the electronic pen main body component 4 of the electronic pen main body module 3 and to be coupled to the pen tip side housing 21.

[0028] In this embodiment, the pen tip side housing part 21 and the rear end side housing part 22 are joined together by a locking structure using a press fit and a ring-shaped concave groove and convex part, but this is not limited to this. For example, threaded parts may be formed on the outer periphery of the pen tip side housing part 21 and the inner wall surface of the rear end side housing part 22, and the two may be configured to be screwed together.

[0029] [Example of configuration of electronic pen main body module 3] Figure 2 is an exploded oblique view of the electronic pen main body module 3, showing the pen tip side housing part 21 and the electronic pen main body component 4 separated, and also showing the group of parts that make up the electronic pen main body component 4 disassembled.

[0030] 2, the electronic pen body component 4 comprises a writing cartridge 5, an eraser cartridge 6, a knock cam mechanism, and a group of parts for axially connecting the writing cartridge 5 and the eraser cartridge so that they move together in the axial direction in response to a knock operation. The knock cam mechanism comprises a cam body, a rotor, a knock bar, and an elastic return member. The elastic return member is used to return the pen tip side of the writing cartridge 5 from a state in which it protrudes from the pen tip-side opening 2a of the pen housing 2 (hereinafter, sometimes referred to as the opening 2a of the pen tip-side housing portion 21) to a state in which it is housed within the pen housing 2.

[0031] The parts group includes a knock case 41 constituting an example of a cam main body, a rear end shaft 42 constituting an example of a knock rod, a front shaft 43 constituting an example of a rotor, a rear end cap member 44 whose rear end serves as the knock operation portion Nk, a gear portion 45, a gear holder portion 46 that holds the gear portion 45, a coil spring 47 constituting an elastic return member, and a spacer 48. In this example, all of the parts in the parts group, except for the coil spring 47, are made of resin.

[0032] The knock case 41 has a tubular shape, in this example, a cylindrical shape, and includes a large-diameter portion 41a whose outer diameter is equal to the above-mentioned diameter Ra, and a small-diameter portion 41b whose outer diameter is slightly smaller than the inner diameter of the gear holder 46. The small-diameter portion 41b is formed with a plurality of grooves 41c and a locking portion 41f that form cam pieces and engage with a plurality of blades 43a that form cam pieces of the front shaft 43 that constitutes an example of a rotor. As will be described later, the grooves 41c engage with the blades 43a when the knock operation is not performed and the nib side of the handwriting input cartridge 5 is housed in the nib-side housing 21, and the locking portion 41f engages with the blades 43a when the handwriting input cartridge 5 is locked in a state where the nib side protrudes from the opening 2a of the nib-side housing 21.

[0033] The rear-end shaft portion 42 is a tubular member, in this example, a cylindrical member, and has an outer diameter smaller than the inner diameter of the cylindrical knock case portion 41. The rear-end shaft portion 42 is configured to be inserted from the rear end into the hollow portion of the knock case portion 41. In this case, a ridge 42a extending in the axial direction is provided at a predetermined angular position in the circumferential direction on the outer peripheral side surface of the rear-end shaft portion 42. The ridge 42a is fitted into a groove (not shown in FIG. 2 ) formed on the inner wall surface of the hollow portion of the knock case portion 41, thereby preventing the rear-end shaft portion 42 from rotating relative to the knock case portion 41.

[0034] A ring-shaped protrusion 42b is formed on the rear end of the rear shaft portion 42. The outer diameter of the ring-shaped protrusion 42b is a diameter Ra, and the rear shaft portion 42 is configured to be inserted into the knock case portion 41 up to the position of the ring-shaped protrusion 42b.

[0035] In this embodiment, the inner diameter of the hollow part of the rear end shaft part 42 is configured to be larger than the outer diameter of the erasing cartridge 6, so that the part of the erasing cartridge 6 opposite to the tip side can be stored in the hollow part of the rear end shaft part 42. However, the end part of the hollow part of the rear end shaft part 42 on the pen tip side has a smaller diameter than the outer diameter of the erasing cartridge 6, so that the erasing cartridge 6 does not move from the rear end shaft part 42 to the pen tip side and remains inside the rear end shaft part 43.

[0036] In this example, the axial length of the rear end shaft portion 42 is set to a length such that when the erasing cartridge 6 is stored in its hollow portion, the pen tip side of the erasing cartridge 6 protrudes from the rear end side shaft portion 42 toward the rear end.

[0037] The rear end cap member 44 has an inner diameter slightly larger than the outer diameter of the rear end shaft portion 42, and is a cylindrical portion whose outer diameter is set equal to the diameter Ra, with the rear end portion closed. The rear end side of this rear end cap member 44 serves as a knock operation portion Nk. The rear end shaft portion 42 has a portion that protrudes further rearward from the position of the ring-shaped protrusion 42b, and by fitting the rear end cap member 44 onto this protruding portion, the front end of the erasing cartridge 6 is covered by the rear end cap member 44.

[0038] In this case, the rear end shaft portion 42 has an engaging protrusion 42c that protrudes further rearward from the position of the ring-shaped protrusion 42b, and the rear end cap member 44 is provided with a through window 44a into which this engaging protrusion 42c fits. When the rear end cap member 44 is coupled to the rear end side of the rear end shaft portion 42, the engaging protrusion 42c fits into the through window 44a, preventing the rear end cap member 44 from easily detaching. However, the rear end cap member 44 can be removed from the rear end shaft portion 42 by pulling the rear end member 44 strongly toward the rear end.

[0039] The front shaft 43, which constitutes an example of a rotor, is disposed such that the side on which a plurality of blades (protrusions) 43a are formed faces the small diameter portion 41b of the knock case 41. The front shaft 43 has a cylindrical shape such that the blades 43a engage with grooves 41c in the small diameter portion 41b of the knock case 41, forming an integral part with the small diameter portion 41b. The blades 43a are provided on the knock case 41 side of the front shaft 43.

[0040] The outer diameter of the front shaft portion 43 is smaller than the inner diameter of the gear holder portion 46, and the front shaft portion 43 is movable in the axial direction within the gear holder portion 46. A gear portion 43b having a serrated shape is formed on the pen tip side of the front shaft portion 43 to rotate the front shaft portion 43 by a predetermined angle by meshing with a gear portion 45 (described later) that is held and provided within the gear holder portion 46.

[0041] In this embodiment, the front shaft portion 43 is coupled to the rear-end shaft portion 42, which is inserted into the knock case portion 41, in a rotatable state with the axial direction as the rotation axis. For this coupling, a coupling protrusion 430 for coupling with the rear-end shaft portion 42 is formed on the tip end portion of the small diameter portion 41b of the front shaft portion 43 on the knock case portion 41 side. Meanwhile, a fitting portion 420 is formed on the pen tip side of the rear-end shaft portion 42, to which the coupling protrusion 430 of the front shaft portion 43 is rotatably coupled.

[0042] Figure 3 is an enlarged view to explain the joint between the rear end shaft portion 42 and the front shaft portion 43, where Figure 3(A) is an enlarged oblique view of the front shaft portion 43, Figure 3(B) is a longitudinal cross-sectional view of the enlarged oblique view of the rear end shaft portion 42, and Figure 3(C) is a longitudinal cross-sectional view of the state in which the rear end shaft portion 42 and the front shaft portion 43 are joined.

[0043] As shown in Fig. 3A, the coupling protrusion 430 formed at the tip of the small-diameter section 41b of the front shaft 43 is composed of two protrusions 431 and 432 formed by separating a cylindrical member by a slit 433 including the centerline of the cylindrical member. The front shaft 43 is made of elastic resin, and the two protrusions 431 and 432 are elastically displaceable toward the slit 433. Furthermore, as shown in Fig. 3A, tapered bulges 431a and 432a are formed on the opposite side of the two protrusions 431 and 432 from the slit 433. The tapered bulges 431a and 432a are formed so that their diameters gradually increase from the tip to halfway along the axial length of the coupling protrusion 430, and engaging steps 431t and 431t are provided halfway along the axial length of the coupling protrusion 430.

[0044] On the other hand, the rear end shaft portion 42 is provided with a fitting portion 420 consisting of a small diameter hole portion 421 having a small diameter into which the coupling protrusion 430 is inserted, and a large diameter hole portion 422 having a diameter larger than the small diameter hole portion 421. A step portion 423 is formed between the small diameter hole portion 421 and the large diameter hole portion 422, with which the protruding pieces 431, 432 of the coupling protrusion 430 engage.

[0045] 3C , the front shaft portion 43 and the rear shaft portion 42 are coupled together by inserting the coupling protrusion 430 of the front shaft portion 43 into the fitting portion 420 of the rear shaft portion 42. That is, when the tip end of the coupling protrusion 430 of the front shaft portion 43 is inserted into the small diameter hole 421 of the fitting portion 420 of the rear shaft portion 42, the two protrusion pieces 431 and 432 that make up the coupling protrusion 430 are displaced toward the slit 433 in a direction intersecting the axial direction, and the coupling protrusion 430 is inserted into the small diameter hole 421 of the fitting portion 420.

[0046] Then, when the coupling protrusion 430 is pushed in so that the tapered bulges 431a and 432a of the two protrusions 431 and 432 are positioned within the space of the large-diameter hole 422 of the fitting portion 420 of the rear-end shaft portion 42, the two protrusions 431 and 432 elastically return to their original state. Then, as shown in Figure 3(C) , the engaging step portions 431t and 432t of the tapered bulges 431a and 432a of the two protrusions 431 and 432 of the coupling protrusion 430 engage with the step portion 423 of the fitting portion 420 of the rear-end shaft portion 42, and the front shaft portion 43 and the rear-end shaft portion 42 remain coupled to each other.

[0047] At this time, when the front shaft portion 43 and the rear end shaft portion 42 are connected, the front shaft portion 43 is not restricted in its rotational movement around the axial direction, and therefore the front shaft portion 43 is able to rotate around the axial direction relative to the rear end shaft portion 42.

[0048] In addition, in Figure 3 (C), the recess 43c provided in the front shaft portion 43 is a fitting recess for fitting a spacer 48 connected to the rear end side of the handwriting input cartridge 5 into this front shaft portion 43, as will be described later.

[0049] Returning to the explanation of the components in Figure 2, the gear portion 45 engages with the front shaft portion 43 to rotate the front shaft portion 43 by a predetermined angle, and in this example, forms part of the rotor portion.

[0050] The gear holder portion 46 is a cylindrical body consisting of a large diameter portion 46a and a small diameter portion 46b, and is configured to fix and hold the gear portion 45 at a predetermined position in the axial direction of its hollow portion.

[0051] The gear portion 45 is fixed and held at a position slightly closer to the pen tip in the axial direction within the large diameter portion 46a of the gear holder portion 46. The axial position of this gear portion 45 within the gear holder portion 46 is selected so that the tip side of the writing input cartridge 5 can be stored within the pen tip side housing portion 21 when not knocking, and can protrude from the opening 2a at the tip of the pen tip side housing portion 21 when knocking.

[0052] The outer diameter of the large-diameter portion 46a of the gear holder 46 is equal to the outer diameter of the cylindrical portion 21b of the nib-side housing 21, and the inner diameter, from the position where the gear portion 45 is held to the rear end, is slightly larger than the outer diameter of the small-diameter portion 41b of the knock case 41, as described above. The diameter, from the position where the gear portion 45 is held to the nib side of the large-diameter portion 46a, is smaller than the diameter at the rear end and equal to or larger than the inner diameter of the small-diameter portion 46b. In this way, the inner diameter changes within the hollow portion of the large-diameter portion 46a of the gear holder 46, and the gear portion 45 is held at a step formed by this change in inner diameter. Therefore, the gear portion 45 is disposed within the gear holder 46 in a state where it cannot move toward the nib in the axial direction.

[0053] The outer diameter of the small diameter portion 46b of the gear holder portion 46 is approximately equal to or slightly smaller than the inner diameter of the cylindrical portion 21b of the pen tip side housing portion 21, and the inner diameter is configured to be larger than the outer diameter of the rear end side of the handwriting input cartridge 5 so that the rear end side of the handwriting input cartridge 5 can be inserted. The gear portion 45 has a ring shape, and the handwriting input cartridge 5 is configured to be able to pass through this gear portion 45.

[0054] 2, the handwriting input cartridge 5 is disposed so that its rear end is housed within the large diameter portion 46a and small diameter portion 46b of the gear holder portion 46, and its front end protrudes from the small diameter portion 46b toward the pen tip side housing portion 21. As will be described later, the handwriting input cartridge 5 is configured so that its rear end is fitted into a spacer 48 via a coil spring 47. The spacer 48 is configured to be locked by being fitted into the recess 43c of the front shaft portion 43, so that the handwriting input cartridge 5 with the spacer 48 fitted into its rear end is locked to the front shaft portion 43 via the spacer 48 when the spacer 48 is fitted into the recess 43c of the front shaft portion 43.

[0055] In this embodiment, as described above, the outer diameter of the front shaft portion 43 is smaller than the inner diameter of the large diameter portion 46a of the gear holder portion 46, and therefore the front shaft portion 43 is movably housed within the large diameter portion 46a of the gear holder portion 46. In addition, the outer diameter of the small diameter portion 41b of the knock case portion 41 is selected to be equal to or slightly smaller than the inner diameter of the large diameter portion 46a of the gear holder portion 46, and by inserting the small diameter portion 41b of the knock case portion 41 into the large diameter portion 46a of the gear holder portion 46, the gear holder portion 46 and the knock case portion 41 are coupled and locked together.

[0056] In this case, in this embodiment, near the joint between the small diameter portion 41b of the knock case portion 41 and the large diameter portion 41a, ring-shaped protrusions 41d and 41e are formed that fit into ring-shaped recessed grooves on the inner wall of the large diameter portion 46a of the gear holder portion 46, thereby joining the gear holder portion 46 and the knock case portion 41 and locking the joined state.

[0057] As described above, the gear holder 46 and the knock case 41 are joined together, whereby the gear holder 46 and the knock case 41 form the case (housing) of the electronic pen main body 4 in this embodiment. As described above, the eraser cartridge 6 is housed inside the rear end shaft 42 joined to the front shaft 43, and the rear end cap member 44 is attached to the rear end shaft 42, thereby forming the electronic pen main body 4.

[0058] In this embodiment, the small diameter portion 46b of the gear holder portion 46 of the electronic pen main body component 4 configured as described above is pressed into the pen tip side housing portion 21, thereby connecting the electronic pen main body component 4 to the pen tip side housing portion 21 and forming the above-mentioned electronic pen main body module 3.

[0059] [Examples of the configuration of the writing input cartridge 5 and the erasing cartridge 6] Figure 4(A) is a diagram showing an example of the configuration of the writing input cartridge 5 of the electronic pen 1 of this embodiment, Figure 4(B) is an enlarged cross-sectional view of the elastic displacement portion 54 provided on the rear end side of the writing input cartridge 5, and Figure 4(C) is a diagram showing an example of the configuration of the erasing cartridge 6.

[0060] 4A , the handwriting input cartridge 5 in the electronic pen 1 of this embodiment is made up of a core body 51, a signal transmitting member 52, a cartridge housing 53, and in this example, an elastic displacement portion 54 provided on the rear end side of the cartridge housing 53. The cartridge housing 53 is made up of a holder portion 531 that holds a writing pressure detection portion 55 and a circuit board 56 on which an electronic circuit is arranged, and a protective cover portion 532 that has the function of storing and protecting the writing pressure detection portion 55 and the circuit board 56 held by the holder portion 531.

[0061] In this example, the core body 51 is made of a relatively hard and elastic resin material, such as POM (Polyoxymethylene), and in this example, a tip portion 51a having a larger diameter than the shaft portion is formed on the pen tip side of the rod-shaped shaft portion.

[0062] The signal transmitting member 52 is composed of a coil 521 that forms a resonant circuit for transmitting and receiving signals to and from the position detection device by electromagnetic induction, and a magnetic core, in this example a ferrite core 522, around which the coil 521 is wound. A through hole 522a is formed in the ferrite core 522 in the axial direction.

[0063] The diameter of the through-hole 522a of this ferrite core 522 is larger than the diameter of the axial portion of the core body 51, and the axial portion of the core body 51 is inserted through this through-hole 522a and fitted into the writing pressure detection unit 55. In this case, the tip portion 51a of the core body 51 is made to protrude beyond the ferrite core 522 as the pen tip, and the end portion 51b on the rear end side of the axial portion of the core body 51 is fitted into the writing pressure detection unit 55. As a result, the pressure (writing pressure) applied to the tip portion 51a of the core body 51 is applied to the writing pressure detection unit 55. The core body 51 is detachable from the writing pressure detection unit 55.

[0064] The pen pressure detection unit 55 is configured, for example, using a mechanism that changes the capacitance of a variable capacitor in response to the applied pressure (pen pressure) (see, for example, Patent Document (JP 2011-186803 A)). Note that the pen pressure detection unit 55 may also use a variable capacitor configured with a semiconductor chip made of MEMS (Micro Electro Mechanical Systems) elements (see, for example, Patent Document (JP 2013-161307 A)). Note that the configuration of the pen pressure detection unit 55 is not limited to this example.

[0065] The circuit board 56 is mounted with electronic components such as a capacitor that, together with the coil 521, forms a resonant circuit, and in this example, a conductor pattern is formed to connect the pen pressure detection unit 55, which is composed of a variable capacitance capacitor, to the resonant circuit.

[0066] The holder portion 531 of the cartridge housing 53 is made of, for example, a resin material, and is fitted with the ferrite core 522 of the signal transmitting member 52. The holder portion 531 is provided with a cylindrical portion (not shown) that holds the pen pressure detection portion 55, and a circuit board mounting portion (not shown) that holds the circuit board 56.

[0067] The protective cover portion 532 of the cartridge housing 53 is composed of a pipe-shaped member made of a hard material, in this example a pipe-shaped member made of metal, and constitutes a circuit portion protective member that protects the electrical circuit components of the pen pressure detection portion 55 and the circuit board 56 held in the holder portion 531.

[0068] That is, the cartridge housing 53 is configured by joining the holder part 531 and the protective cover part 532 in the axial direction, with a part of the cylindrical part that holds the pen pressure detection part 55 of the holder part 531 and the circuit board mounting base part being housed in the hollow part of the protective cover part 532. In this case, as shown in Fig. 4(A) , the diameter of the cylindrical part of the holder part 531 and the diameter of the pipe-shaped member that makes up the protective cover part 532 are the same, R0.

[0069] As shown in Figures 4 (A) and (B), in this example, the elastic displacement portion 54 is configured by loosely fitting a coil spring 542 in a freely expandable state into a rod-shaped member 541 made of, for example, resin, which is thinner than the inner diameter of the protective cover portion 532 of the cartridge housing 53. In this example, one axial end 541a of the rod-shaped member 541 is inserted and connected to the opening on the rear end side of the protective cover portion 532 of the cartridge housing 53.

[0070] One axial end 541a of the rod-shaped member 541 is smaller than the inner diameter of the protective cover portion 532 and has a diameter slightly larger than that of an intermediate portion 541m in which the coil spring 542 is loosely fitted. The other axial end 541b of the rod-shaped member 541 is configured to have a larger diameter than that of the intermediate portion 541m. A fitting protrusion 543 for fitting the handwriting input cartridge 5 into the recess 43c of the front shaft portion 43 is formed in the center of the circular end surface of the other end 541b.

[0071] A ring-shaped member 544 is provided on one end 541a side of intermediate portion 541m of rod-shaped member 541. This ring-shaped member 544 has a portion whose outer diameter is approximately equal to or slightly smaller than the inner diameter of the opening on the rear end side of protective cover portion 532, and a flange portion 544a whose outer diameter is equal to the outer diameter R0 of protective cover portion 532, and is configured so that its inner diameter is smaller than the outer diameter of one end 541a of rod-shaped member 541 and larger than that of intermediate portion 541m.

[0072] The diameter of the coil spring 542 is selected to be larger than the diameter of the intermediate portion 541m of the rod-shaped member 541 and smaller than the diameter R0 of the protective cover portion 532 and the other end 541b of the rod-shaped member 541. Therefore, the coil spring 542 is held in the intermediate portion 541m between the ring-shaped member 544 press-fitted into the opening on the rear end side of the protective cover portion 532 of the cartridge casing 53 and the other end 541b of the rod-shaped member 541. In this held state, the coil spring 542 is in a state in which it elastically biases the ring-shaped member 544 side on the rear end side of the protective cover portion 532 of the cartridge casing 53 and the other end 541b side of the rod-shaped member 541 so as to separate them from each other by its elastic displacement force.

[0073] The elastic displacement part 54 configured as described above is attached to the rear end side of the protective cover part 532 by inserting one end part 541a into the protective cover part 532 from the opening on the rear end side of the protective cover part 532. In this way, the elastic displacement part 54 is attached in a state where the middle part 541m of the rod-shaped member 541 in which the coil spring 542 is loosely fitted and the other end part 541b are exposed to the outside of the protective cover part 532.

[0074] The outer diameter of one end 541a of the rod-shaped member 541 is smaller than the inner diameter of the protective cover part 532, and the middle part 541m of the rod-shaped member 541 is movable in the axial direction relative to the ring-shaped member 544 fixed to the protective cover part 532 against the elastic biasing force of the coil spring 542. As a result, the one end 541a side of the rod-shaped member 541 of the elastic displacement part 54 is movable toward the pen tip within the hollow part of the protective cover part 532 against the elastic force of the coil spring 542.

[0075] In this embodiment, by attaching the elastic displacement portion 54 to the rear end side of the cartridge housing 53 as described above, the handwriting input cartridge 5 is formed as shown in FIG. 4A . When a load equal to or greater than a predetermined value is applied to the handwriting input cartridge 5, which attempts to contract the axial length of the handwriting input cartridge 5 against the elastic displacement force of the coil spring 542 of the elastic displacement portion 54, the coil spring 542 of the elastic displacement portion 54 elastically contracts, and one end 541 a of the rod-shaped member 541 moves toward the pen tip within the protective cover portion 532, thereby displacing the handwriting input cartridge 5 in the axial direction. When this load is removed, the coil spring 542 elastically returns to its original expanded state, and the axial length of the handwriting input cartridge 5 returns to the original state shown in FIG. 4A .

[0076] In this case, the elastic properties of the coil spring 542 are insensitive to loads within the range of writing pressure applied to the tip 51 a of the core 51 when the electronic pen 1 is in use. That is, the elastic properties of the coil spring 542 are insensitive to loads within the range of writing pressure values ​​detected by the writing pressure detection unit 55. The coil spring 542 has elastic properties that allow it to expand and contract as described above when a load greater than the load within the range of writing pressure applied to the tip 51 a of the core 51 is applied by a knocking operation by the user when the electronic pen 1 is in use, the load being larger than the load within the range of writing pressure, or when an impact load greater than the load within the range of writing pressure, is applied to the electronic pen 1. The latter expansion and contraction in response to the impact load means that the elastic displacement unit 54 acts as a so-called shock absorber for the writing input cartridge 5.

[0077] As is clear from the above-described configuration, the elastic displacement portion 54 is detachable from the protective cover portion 532 of the handwriting input cartridge 5 .

[0078] The elastic characteristics of the coil spring 47 serving as the elastic return member in the above-mentioned knock cam mechanism are the same as those used in general knock-type ballpoint pens, and have a smaller elastic force than the coil spring 542 of the elastic displacement portion 54.

[0079] 4A and 5, in the handwriting input cartridge 5 of this embodiment, a protruding portion 57 is provided at a predetermined position between one axial end and the other axial end of the cartridge housing 53. The protruding portion 57 protrudes from the outer peripheral side surface of the cartridge housing 53 in a direction intersecting the axial direction, in this example, a direction perpendicular to the axial direction. In this embodiment, the protruding portion 57 is provided on the holder portion 531 on the pen tip side of the cartridge housing 53. In this example, the protruding portion 57 is configured to protrude from the outer peripheral side surface of the holder portion 531 into a flange-like portion of a predetermined thickness. The protruding portion 57 may be configured integrally with the outer housing of the holder portion 531, or may be configured separately from the holder portion 531.

[0080] In this case, the protruding portion 57 may be formed to protrude (project) in a direction perpendicular to the axial direction around the entire outer periphery of the holder portion 531, but in this embodiment, as shown in Fig. 5, it is shaped to protrude in a direction perpendicular to the axial direction from positions 180 degrees apart by an amount equal to the width of the diameter of the holder portion 531. The tip of the protruding portion 57 in the axial direction has an arc shape so that it fits along the inner wall surface of the pen tip side housing portion 21 of the pen housing 2.

[0081] By configuring it in this shape, the contact area between the axial tip of the protrusion 57 and the inner wall surface of the pen tip side housing part 21 of the pen housing 2 is reduced as much as possible, making it easier for the writing input cartridge 5 to move axially within the pen housing 2 when a knock operation is performed or when an impact load is applied.

[0082] Furthermore, because the protruding portion 57 is formed in the shape described above, a space is formed between the protruding portion 57 and the inner wall surface of the pen tip side housing 21 on the side of the protruding portion 57 in a direction intersecting the protruding direction. In this example, a protrusion or a locking piece is provided in this space at the protruding portion 57 to prevent rotation of the handwriting input cartridge 5 around the axial direction within the pen housing 2. Furthermore, the end (lead portion) of the coil 521 is passed through this space toward the holder portion 531 without contacting the inner wall of the pen tip side housing 21. Note that the end of the coil 521 may be guided toward the holder portion 531 by providing a recess in the protruding portion 57 so that it does not protrude outward from the recess.

[0083] Fig. 6(A) is a cross-sectional view of the pen tip side of the pen tip side housing part 21 of the pen housing 2, and Fig. 6(B) is a view showing the pen tip side of the handwriting input cartridge 5. In this embodiment, as shown in Fig. 6(A), the inner wall surface of the pen tip side housing part 21 is formed with a step part 21s in this example as a stopper part that engages with a protruding part 57 provided on the cartridge housing 53 of the handwriting input cartridge 5 to prevent further movement of the handwriting input cartridge 5 toward the pen tip side of the pen tip side housing part 21 of the pen housing 2.

[0084] In the electronic pen 1, when writing on the input surface of the position detection sensor, the axial length (specified protrusion length Lp) that the pen tip side of the writing input cartridge 5 should protrude to the outside from the opening 2a of the pen housing 2 (pen tip side opening of the pen tip side housing part 21) is predetermined taking into consideration the ease of input operation by the user, etc.

[0085] In this embodiment, the protrusion 57 provided on the cartridge housing 53 of the writing input cartridge 5 and the step 21s formed on the inner wall surface of the pen tip side housing portion 21 of the pen housing 2 are positioned in the axial direction so that they engage when the protrusion length from the opening 2a of the pen housing 2 on the pen tip side of the writing input cartridge 5 reaches the above-mentioned specified protrusion length Lp.

[0086] The relationship between the formation position of the protrusion 57 provided on the cartridge housing 53 of the writing input cartridge 5 in this embodiment and the formation position of the step portion 21s formed on the inner wall surface of the pen tip side housing portion 21 will be further explained with reference to Figure 6.

[0087] As shown in Figure 6 (B), the writing input cartridge 5 has a signal transmitting member 52 consisting of a ferrite core 522 around which a coil 521 is wound attached to a holder portion 531 on the pen tip side of a cartridge housing 53 having an outer diameter of R0, and further, the core body 51 is inserted through a through hole 522a of the ferrite core 522 and engaged with a pen pressure detection portion 55 (not shown in Figure 6) arranged in the holder portion 531.

[0088] 6B, the outer diameter R1 of the ferrite core 522 is smaller than the outer diameter R0 of the cartridge housing 53. The outer diameter R2 of the portion of the ferrite core 522 around which the coil 521 is wound is equal to or smaller than the outer diameter R0 of the cartridge housing 53. In other words, the relationship R1<R2≦R0 is satisfied.

[0089] As shown in Figure 6 (A), the diameter R3 of the opening 2a on the pen tip side of the pen tip side housing portion 21 is slightly larger than the outer diameter R1 of the ferrite core 522 of the writing input cartridge 5, and in this example, when the electronic pen 1 is in use, not only the core body 51 but also a portion of the ferrite core 522 is configured to be exposed to the outside from the opening 2a.

[0090] 6(B), the length in the axial direction from the tip of the tip portion 51a of the core body 51 to a part of the ferrite core 522 on the pen tip side is set to be the specified protrusion length Lp. Also, as shown in FIG. 6(B), the length in the axial direction from the tip of the tip portion 51a of the core body 51 to the end face on the pen tip side of the protrusion portion 57 of the holder portion 531 of the cartridge housing 53 of the handwriting input cartridge 5 is set to be Lz.

[0091] 6A, the inner diameter R4 of the hollow portion of the nib portion that communicates with the opening 2a of the nib-side housing 21 is slightly larger than the outer diameter R0 of the handwriting input cartridge 5, and the coil 521 wound around the ferrite core 522 that constitutes the signal transmitting member 52 does not come into contact with the inner wall surface of the nib-side housing 21 in the hollow portion with the inner diameter R4. In this example, as shown in FIG. 6A, the hollow portion 21e of the nib-side housing 21 has a tapered shape that gradually decreases in diameter from the portion with the inner diameter R4 to the opening 2a with the diameter R3. Therefore, if the coil 521 of the handwriting input cartridge 5 were to be positioned in the tapered portion, there is a risk that the coil 521 would come into contact with the inner wall surface of the tapered portion.

[0092] Therefore, in this example, as shown in Figures 6(A) and (B), in the axial direction, the length from a position rearward of the tip of the core body 51 of the writing input cartridge 5 by the specified protrusion length Lp to the end of the wound portion of the coil 521 on the pen tip side is configured to be equal to the length L2 from the tip of the opening 2a of the pen tip side housing portion 21, via the tapered portion, to the end of the pen tip side of the inner diameter R4.

[0093] 6A and 6B, the inner diameter of the hollow portion 21e of the pen tip side housing 21 from the position of a length L1 (=Lz-Lp) equal to Lz-Lp from the tip of the opening 2a of the pen tip side housing 21 toward the rear end is set to a diameter R5 which is larger than the inner diameter R4 and the outer diameter R0. As a result, a step 21s is formed at a position of the length L1 (=Lz-Lp) equal to Lz-Lp from the tip of the opening 2a of the pen tip side housing 21.

[0094] Therefore, as shown in FIG. 6A, in the pen tip side housing 21 of the electronic pen 1 of this embodiment, the length of the portion corresponding to the diameter R4 on the pen tip side is length L3 (= L1 - L2). When the pen tip side of the handwriting input cartridge 5 protrudes by the specified protrusion length Lp, the coil 521 of the handwriting input cartridge 5 shown in FIG. 6B is positioned in the portion of the hollow portion 21e of the pen tip side housing 21 that is the length L3 of this diameter R4. Therefore, the coil 521 does not come into contact with the inner wall of the hollow portion 21e of the pen tip side housing 21. Therefore, the coil 521 is not subjected to unnecessary load due to contact, and can be coupled to the position detection sensor with a stable magnetic flux by the signal transmitting member 52.

[0095] The diameter of the arcuate portion at the tip in the protruding direction of the overhanging portion 57 formed on the holder portion 531 of the cartridge housing 53 of the handwriting input cartridge 5 is set to a diameter R6 that is larger than the inner diameter R4 of the hollow portion on the pen tip side of the position of the step portion 21s of the pen tip side housing 21, and is substantially equal to or slightly smaller than the inner diameter R5 of the pen tip side housing 21. In other words, the relationship R4<R6≦R5 is satisfied.

[0096] With the above-described configuration, the protruding portion 57 of the handwriting input cartridge 5 engages with the step portion 21s on the inner wall surface of the pen tip side housing portion 21, thereby preventing the handwriting input cartridge 5 from moving toward the pen tip side within the hollow portion of the pen housing 2. In this state, the pen tip side core body 51 and a portion of the ferrite core 522 of the handwriting input cartridge 5 can protrude outward from the opening 2a of the pen tip side housing portion 21 of the pen housing 2 by the specified protrusion length Lp.

[0097] Therefore, the electronic pen 1 is always maintained in a state where its pen tip side protrudes outward from the opening 2a by the specified protrusion length Lp, and the coil 521, which is an example of a part on the pen tip side of the writing input cartridge 5 that should not come into contact with the inner wall surface of the pen tip side housing part 21, is prevented from coming into contact with the inner wall surface of the pen tip side housing part 21.

[0098] Moreover, in this embodiment, the diameter of the arc-shaped portion at the tip of the protruding portion 57 provided on the handwriting input cartridge 5 in the protruding direction is set to a diameter R6 that is approximately equal to or slightly smaller than the inner diameter R5 of the pen tip side housing 21, so that the handwriting input cartridge 5 is also prevented from displacement in a direction perpendicular to the axial direction. This also makes it possible to prevent the coil 521, which is an example of a part on the pen tip side of the handwriting input cartridge 5 that should not come into contact with the inner wall surface of the pen tip side housing 21, from coming into contact with the inner wall surface of the pen tip side housing 21.

[0099] In the electronic pen 1 of this embodiment, the protrusion 57 of the handwriting input cartridge 5 engages with the step 21s on the inner wall surface of the pen tip side housing 21, so that the pen tip side of the handwriting input cartridge 5 does not protrude outward from the opening 2a of the pen tip side housing 21 by more than the specified protrusion length Lp. Therefore, even during a knock operation, protrusion by more than the specified protrusion length Lp is prevented. In this respect, too, the coil 521, which is an example of a part on the pen tip side of the handwriting input cartridge 5 that should not come into contact with the inner wall surface of the pen tip side housing 21, can be prevented from coming into contact with the inner wall surface of the pen tip side housing 21.

[0100] 4C shows an example of the configuration of the eraser cartridge 6 in the electronic pen 1 of this embodiment. The eraser cartridge 6 of this example has the same configuration as the above-described handwriting input cartridge 5, with the rear end elastic displacement portion 54 and the protruding portion 57 removed.

[0101] That is, the eraser cartridge 6 in the electronic pen 1 of this embodiment will be described by assigning reference numerals in the 60s to the same parts as those in the writing input cartridge 5 described above, and as shown in Figure 4(C), the eraser cartridge 6 in the electronic pen 1 of this embodiment comprises a core body 61, a signal transmitting member 62, and a cartridge housing 63. The cartridge housing 63 comprises a holder part 631 that holds a writing pressure detection part 65 and a circuit board 66 on which an electronic circuit is arranged, and a protective cover part 632 that has the function of housing and protecting the writing pressure detection part 65 and the circuit board 66 held in the holder part 631.

[0102] The signal transmitting member 62 is composed of a coil 621 that forms a resonant circuit for transmitting and receiving signals to and from the position detection device using electromagnetic induction, and a magnetic core around which the coil 621 is wound, a ferrite core 622 in this example. A through-hole 622a is formed in the ferrite core 622 in the axial direction. The core body 61 is inserted through this through-hole 622a and fitted into the writing pressure detection unit 55. In this case, the tip portion 51a of the core body 51 protrudes beyond the ferrite core 522 as the pen tip.

[0103] The configuration of each part of the erasing cartridge 6 with the reference numbers in the 60s mentioned above is the same as that described using the reference numbers in the 50s in the writing input cartridge 5 mentioned above, so detailed description of them will be omitted here.

[0104] [Assembly Procedure of Electronic Pen Body Module 3 of the Embodiment] The electronic pen body module 3 of this embodiment having the above-described configuration can be assembled by sequentially assembling the above-described components. The assembly procedure of the electronic pen body module 3 of this embodiment will be described below with reference to FIGS. 7 to 11.

[0105] First, as shown in Fig. 7(A), with the knock case 41 at the center, the shaft 42 is aligned axially on the rear end side of the knock case 41, and the front shaft 43 is aligned on the pen tip side. Then, the rear end shaft 42 is housed in the knock case 41 through the rear end opening 41g of the knock case 41, and the coupling protrusion 430 of the front shaft 43 is fitted into the fitting portion 420 of the rear end shaft 42, as described with reference to Fig. 3, to assemble the assembly part 101AS that constitutes the main part of the knock cam mechanism, as shown in Fig. 7(B).

[0106] In this case, when the rear-end shaft portion 42 is housed in the knock case portion 41, the groove 41h formed on the inner wall surface of the knock case portion 41, which is exposed on the opening 41g side of the knock case portion 41, is aligned with the ridge 42a of the rear-end shaft portion 42 so that the ridge 42a is housed in the groove 41h. The engagement between the groove 41h of the knock case portion 41 and the ridge 42a of the rear-end shaft portion 42 prevents the rear-end shaft portion 42 from rotating relative to the knock case portion 41.

[0107] 7B, the rear shaft portion 42 is coupled to the front shaft portion 43 and is movable axially within the knock case portion 41. In this case, the axial length of the recessed groove 41h of the knock case portion 41 is formed relatively long, and the rear shaft portion 42 is configured to move axially at least the amount of the axial stroke during the knock operation with the ridge 42a engaged with the recessed groove 41a.

[0108] Next, as shown in FIG. 8A, with the gear holder portion 46 at the center, the writing input cartridge 5 is aligned on the pen tip side of the gear holder portion 46, and the coil spring 47 and spacer 48 are aligned on the rear end side in the axial direction.

[0109] 8(B), the rear end of the handwriting input cartridge 5 is inserted into the hollow portion of the gear holder portion 46, and the ring-shaped gear portion 45 is inserted through it. The coil spring 47 is then wound around the rear end through which the gear portion 45 has been inserted, and the fitting protrusion 543 provided at the end of the elastic displacement portion 54 is fitted into the fitting recess 48a of the spacer 48. The partial cross-sectional view of FIG. 8(C) shows the fitting protrusion 543 of the elastic displacement portion 54 of the handwriting input cartridge 5 and the spacer 48.

[0110] As shown in Figures 8(A) to (C), ring-shaped protrusions 46c and 46d that fit into the recessed grooves of the pen tip side housing part 21 are formed on the outer periphery of the small diameter part 46b of the gear holder part 46.

[0111] 8, the coil spring 47 for elastically returning the knock cam mechanism is disposed between the spacer 48 and the step 46e on the inner wall of the gear holder 46 where the gear 45 is provided, so as to cover the rear end of the elastic displacement portion 54 and the protective cover portion 532 of the handwriting input cartridge 5. This allows the handwriting input cartridge 5 to move axially within the hollow portion of the gear holder 46, but the presence of the coil spring 47 and the spacer 48 forms an assembly 102AS that will not fall off toward the pen tip side.

[0112] 8A, 8B, and 8C are slightly different in scale for ease of explanation, and the same applies to the following figures.

[0113] Next, as shown in FIG. 9(A), the assembly part 101AS constituting the main part of the knock cam mechanism shown in FIG. 7(B) is arranged axially on the rear end side of the assembly part 102AS shown in FIG. 8(B) with the gear part 43b side of the front shaft part 43 facing the gear holder part 46 side.

[0114] 9(B), the front shaft 43 and the small diameter portion 41b of the knock case 41 of the assembly 101AS are inserted into the gear holder 46, and the coupled state of the two is maintained by fitting the ring-shaped protrusions 41d and 41e of the small diameter portion 41b into the ring-shaped recessed grooves 46f and 46g formed on the inner wall surface of the gear holder 46. Furthermore, the spacer 48 coupled to the fitting protrusion 543 of the elastic displacement portion 54 of the handwriting input cartridge 5 of the assembly 102AS is pressed into and fitted into the fitting recess 43c (see FIG. 9(C)) of the small diameter portion 43b of the front shaft 43 of the assembly 101AS, thereby forming the assembly 103AS.

[0115] The partial cross-sectional view of Figure 9(C) shows the mating state in which the spacer 48 connected to the mating protrusion 543 of the elastic displacement portion 54 at the rear end of the handwriting input cartridge 5 is mated with the mating recess 43c of the small diameter portion 43b of the front shaft portion 43 in this assembly part 103AS.

[0116] Next, as shown in FIG. 10A, the pen tip side housing 21 is disposed on the pen tip side of the assembly 103AS shown in FIG. 9B, which is assembled by joining the assembly 101AS and the assembly 102AS.

[0117] 10(B), the pen tip side of assembly 103AS is inserted into pen tip side housing 21, and then the small diameter portion 46b of gear holder 46 is inserted. Then, ring-shaped protrusions 46c and 46d of small diameter portion 46b of gear holder 46 are fitted into a ring-shaped groove (not shown) formed on the inner wall surface of pen tip side housing 21, thereby maintaining the connection between the two and forming assembly 104AS shown in FIG. 10(B). The engagement between ring-shaped protrusions 46c and 46d and the ring-shaped groove can be released by pulling pen tip side housing 21 in a direction that removes it from assembly 104AS in the axial direction.

[0118] Next, as shown in FIG. 11A, the erasing cartridge 6 and the rear end cap member 44 are arranged side by side on the rear end side of the assembly part 104AS shown in FIG. 10B.

[0119] The eraser cartridge 6 is then inserted into the rear end shaft 42 of the assembly part 104AS on the side opposite to the pen tip side. After that, the rear end cap member 44 is placed over the pen tip side of the eraser cartridge 6, and the engaging protrusion 42c of the rear end shaft 42 is fitted into the through window 44a of the rear end cap member 44, thereby joining the rear end cap member 44 to the rear end shaft 42. In this way, the electronic pen body module 3 of this embodiment is constructed, as shown in FIG. 11(B).

[0120] 1 , the rear end housing 22 is coupled to the tip side housing 21 with the rear end of the electronic pen main body module 3 housed therein, thereby forming the electronic pen 1 of this embodiment. This coupled state is maintained by fitting the mating protrusions 22a and 22b on the inner wall of the rear end housing 22 into the ring-shaped recessed grooves 21c and 21d of the tip side housing 21. The coupled state of the tip side housing 21 and the rear end side housing 22 can be separated by pulling them apart, which releases the engagement between the ring-shaped recessed grooves 21c and 21d of the tip side housing 21 and the mating protrusions 22a and 22b on the inner wall of the rear end side housing 22.

[0121] The rear end cap member 44 can be separated from the assembly part 104AS by pulling it in the axial direction while disengaging the through window portion 44a of the rear end cap member 44 from the engaging protrusion portion 42c of the rear end shaft portion 42.

[0122] As described above, the electronic pen 1 of the above-described embodiment can be manufactured by assembling the components constituting the electronic pen 1 in order in the axial direction. Furthermore, because no adhesive is used, the electronic pen 1 can be disassembled in the reverse order of the above procedure. Therefore, if any component, including the writing input cartridge 5 and the erasing cartridge 6, is damaged or deteriorates over time, the electronic pen 1 can be repaired by replacing only that component. In other words, even if a component malfunctions, it is not necessary to replace the entire electronic pen 1, which is economical.

[0123] [Usage of Electronic Pen 1 of Embodiment and Operation During Knocking Operation] In the electronic pen 1 of this embodiment, similar to a knock-type ballpoint pen or other writing instrument, when performing handwriting input using the handwriting input cartridge 5, the knock operation portion Nk at the rear end of the rear end cap member 44 is pressed down (knocked) to cause the nib of the handwriting input cartridge 5 to protrude from the opening 2 a of the nib-side housing portion 21 of the pen housing 2. Then, when the nib of the handwriting input cartridge 5 protrudes from the opening 2 a of the nib-side housing portion 21 of the pen housing 2, a further knock operation returns the nib of the handwriting input cartridge 5 to its original state where it is housed and protected within the nib-side housing portion 21.

[0124] However, in this embodiment of the electronic pen 1, the operation during the knock operation differs from that of a knock-type ballpoint pen, a writing instrument, in that the knock operation involves not only the coil spring 47 of the return elastic member, but also the coil spring 542 of the elastic displacement portion 54 of the handwriting input cartridge 5, as well as the protrusion portion 57 of the handwriting input cartridge 5 and the step portion 21s in the pen tip side housing portion 21.

[0125] In addition, in this embodiment of the electronic pen 1, the electronic pen main body module 3 is configured so that knocking operations are possible when the rear end housing part 22 is not attached, so the following explanation will be given as the operation of the electronic pen main body module 3.

[0126] Figure 12 (A) shows the state in which the pen tip side of the writing input cartridge 5 is stored in the pen tip side housing part 21 in the electronic pen main body module 3 of this embodiment of the electronic pen 1, and Figure 12 (B) shows a longitudinal cross-sectional view of the same.

[0127] 12B, the pen tip side of the handwriting input cartridge 5 is housed within the pen tip side housing 21. In this state, the elastic return coil spring 47 and the elastic displacement portion 54 are in their initial, most extended states. The protruding portion 57 of the handwriting input cartridge 5 and the step portion 21s on the inner wall surface of the pen tip side housing 21 are spaced apart in the axial direction.

[0128] Next, Figure 13 (A) shows the state in which the pen tip side of the writing input cartridge 5 protrudes to the outside from the opening 2a of the pen tip side housing part 21 in the electronic pen main body module 3 of this embodiment of the electronic pen 1, and Figure 13 (B) shows a longitudinal cross-sectional view of this state.

[0129] 13A, at this time, the wing portions 43a of the front shaft portion 43 of the electronic pen main body module 3 engage with the locking portions 41f of the small-diameter portion 41b of the knock case portion 41, and as shown in FIG. 13B, the nib side of the handwriting input cartridge 5 is held in a state in which it protrudes from the opening 2a of the nib-side housing portion 21. In this state, the elastic return coil spring 47 is elastically displaced. Meanwhile, the elastic displacement portion 54 is elastically displaced once during the knock operation that causes the nib side of the handwriting input cartridge 5 to protrude from the opening 2a of the nib-side housing portion 21, but has returned to its original length when the knock operation shown in FIG. 13 is completed.

[0130] In this state, as shown in Figure 13 (B), the protrusion 57 of the handwriting input cartridge 5 and the step 21s on the inner wall surface of the pen tip side housing portion 21 are engaged, and the amount by which the pen tip side of the handwriting input cartridge 5 protrudes from the opening 2a of the pen tip side housing portion 21 is the specified protrusion length Lp, which is a predetermined appropriate amount.

[0131] In this embodiment, since the front shaft portion 43 and the rear shaft portion 42 are coupled together, when the pen tip side of the writing cartridge 5 protrudes as shown in Fig. 13(B), the rear cap member 44 is pushed in and locked. Therefore, even when the rear cap member 44 is turned toward the position detection sensor to use the eraser cartridge 6 in this state, the knock operation portion Nk does not become free as in a knock-type ballpoint pen, and it is easy to use when issuing an erase command.

[0132] Furthermore, as will be described later, in the electronic pen 1 of this embodiment, in order to re-store the pen tip side of the handwriting input cartridge 5 into the pen tip side housing 21 by knocking from the state shown in Figure 13(B), it is necessary to apply a large load that will contract the coil spring 542 of the elastic displacement portion 54 at the rear end of the handwriting input cartridge 5, and therefore the knock mechanism is not activated by the writing pressure of the order of magnitude used when specifying an erasure position with the eraser cartridge 6. In this respect, too, the eraser cartridge 6 is easy to use when specifying erasure.

[0133] The movement of the pen tip side of the electronic pen 1 of this embodiment when the electronic pen main body module 3 is knocked will be further described in comparison with the movement of the pen tip side of a conventional knock-type electronic pen 1PR.

[0134] 14A and 14B are diagrams illustrating the movement of the pen tip side of the electronic pen main body 3PR during a knock operation of a conventional knock-type electronic pen 1PR. Fig. 14A shows a non-extended state in which the pen tip side of the electronic pen main body 3PR is housed within the pen housing 2PR. Fig. 14B shows a state in which, from the state shown in Fig. 14A, a user of the electronic pen 1PR presses down on the knock rod 12PR of the knock cam mechanism 10PR, causing the pen tip side of the electronic pen main body 3PR to protrude by a specified protrusion length Lp from the opening of the pen housing 2PR.

[0135] In the conventional knock-type electronic pen 1PR, in the state shown in Figure 14 (B), the extension operation of the pen tip portion of the electronic pen main body 3PR is not complete, and when the pressing operation of the knock rod 12PR is stopped, the elastic displacement force of the return spring (not shown in Figure 14) of the knock cam mechanism 10PR causes the electronic pen main body 3PR to return to the non-extended state shown in Figure 14 (A).

[0136] From the state shown in Fig. 14(B), the user further pushes in the knock rod 12PR, causing the pen tip of the electronic pen main body 3PR to protrude from the opening of the pen housing 2PR by the specified protrusion length Lp or more, as shown in Fig. 14(C). This causes the rotor of the knock cam mechanism 10PR to rotate, and as shown in Fig. 14(D), the knock cam mechanism 10PR locks in a state in which the pen tip of the electronic pen main body 3PR protrudes from the opening of the pen housing 2A by the specified protrusion length Lp, completing the extension operation.

[0137] Then, from the usage state of the electronic pen 1PR in which the pen tip portion is extended by the specified protrusion length Lp as shown in Figure 14(D), if the knock rod 12PR is further pressed so that the pen tip portion of the electronic pen main body portion 3PR again protrudes from the opening of the pen housing 2PR by more than the specified protrusion length Lp as shown in Figure 14(E), the rotor portion of the knock cam mechanism portion 10PR rotates, the extension lock state is released, and the elastic displacement force of the return spring of the knock cam mechanism portion 10PR (which corresponds to the coil spring 47 although not shown in Figure 14) returns the electronic pen main body portion 3PR to the non-extended state in which the pen tip side of the electronic pen main body portion 3PR shown in Figure 14(A) is stored within the pen housing 2PR as shown in Figure 14(F).

[0138] As described above, in the case of a conventional knock-type electronic pen 1PR, as shown in Figures 14 (C) and (E), it is necessary to move the electronic pen main body 3PR toward the opening of the pen housing 2PR so that the pen tip of the electronic pen main body 3PR protrudes over a protrusion length greater than the specified protrusion length Lp.In this state, after many years of use, there is a risk that the coil of the signal transmitting component, which is an example of a part on the pen tip side of the electronic pen main body 3PR that should not come into contact with the inner wall surface of the pen housing 2PR, will come into contact with the inner wall surface of the pen housing 2PR.

[0139] Furthermore, for example, if an erasing position indicator is provided on the knock rod 12PR of the knock cam mechanism 10PR, when the electronic pen 1PR is in use with the pen tip extended by the specified projection length Lp as shown in Figure 14(D), if the knock rod 12PR is pressed against the position detection sensor to use the erasing position indicator, the pressure (load) of the pressure will cause the knock cam mechanism 10PR to perform a knocking operation, resulting in a problem of poor usability. Furthermore, since the knock rod 12PR and the rotor part of the knock cam mechanism 10PR are generally not connected, the knock rod 12PR will freely move back and forth between the position shown by the dotted line and the position shown by the solid line in Figure 14(D), resulting in a problem of poor usability.

[0140] Next, the movement of the pen tip side of the writing input cartridge 5 and the movement of the knock cam mechanism when the electronic pen 1 of this embodiment is knocked will be described with reference to FIGS.

[0141] 15A shows a non-extended state in which the pen tip side of the handwriting input cartridge 5 is housed in the pen tip side housing portion 21 of the pen housing 2 of the electronic pen main body module 3. In this state, the step portion 21s of the pen tip side housing portion 21 and the protruding portion 57 of the handwriting input cartridge 5 are spaced apart in the axial direction and are not in an engaged state.

[0142] Then, from the state shown in Figure 15 (A), when the user of the electronic pen 1 presses down the knock operation portion Nk at the rear end of the rear end cap member 44 against the elastic force of the coil spring 47 which serves as the return elastic member of the knock cam mechanism portion, causing the pen tip side of the handwriting input cartridge 5 to protrude by the specified protrusion length Lp from the opening 2a of the pen tip side housing portion 21, as shown in Figure 15 (B), the step portion 21s of the pen tip side housing portion 21 and the protrusion portion 57 of the handwriting input cartridge 5 engage, and the pen tip side of the handwriting input cartridge 5 no longer moves in the direction of protruding from the opening 2a within the pen tip side housing portion 21.

[0143] However, in the state shown in Figure 15 (B), the extension operation of the pen tip portion of the handwriting input cartridge 5 is not complete, and the wing portion 43a of the front shaft portion 43 that constitutes the rotor portion has not completely come out of the groove portion 41c of the small diameter portion 41b of the knock case portion 41. When the pressing operation of the knock operation portion Nk is stopped, the elastic displacement force of the return coil spring 47 causes the handwriting input cartridge 5 to return to the non-extended state shown in Figure 15 (A).

[0144] 15(B), when the user applies a large pressure (load) to the knock operation portion Nk against the elastic displacement force of the coil spring 542 of the elastic displacement portion 54 at the rear end of the handwriting input cartridge 5, thereby pushing the rear end cap member 44 toward the pen tip, the protrusion length from the opening 2a on the pen tip side of the handwriting input cartridge 5 remains the specified protrusion length Lp, but the elastic displacement portion 54 at the rear end of the handwriting input cartridge 5 contracts axially as shown in FIG. 15(C). In response to this, as shown in FIG. 15(C), the front shaft portion 43 constituting the rotor moves axially, and the blade portion 43a thereof disengages from the groove portion 41c in the small diameter portion 41b of the knock case portion 41. At the same time, the front shaft portion 43 and the gear portion 45 begin to engage with each other, and a rotational force begins to be applied to the front shaft portion 43.

[0145] 16A, when the front shaft portion 43 and the gear portion 45 are completely engaged, the front shaft portion 43, which constitutes the rotor portion, rotates a predetermined angle. At this time, as described above, the front shaft portion 43 is rotatably coupled to the rear end shaft portion 42, so the rear end shaft portion 42 does not rotate. The handwriting input cartridge 5 is prevented from rotating by engaging a convex portion on the inner wall surface of the pen tip side housing portion 21 at the protrusion 57. However, because the fitting protrusion 543 of the elastic displacement portion 54 on the rear end side of the handwriting input cartridge 5 is fitted into the fitting recess 43c of the front shaft portion 43 via the spacer 48, the front shaft portion 43 rotates without applying excessive load.

[0146] Thereafter, when the load applied to the knock operation unit Nk is reduced, the protrusion 57 of the handwriting input cartridge 5 and the step 21s of the pen tip side housing 21 are engaged, and therefore, the elastic displacement force of the coil spring 542 of the elastic displacement unit 54 of the handwriting input cartridge 5 acts to separate the front shaft unit 43 from the gear unit 45, as shown in FIG. 16(B). Then, as shown in FIG. 16(B), the front shaft unit 43 rotates while the wing 43a moves along the inclination of the locking portion 41f of the small diameter portion 41b of the knock case 41, and as shown in FIG. 16(C), the wing 43a is locked in engagement with the locking portion 41f. In this state, the elastic displacement unit 54 returns to its original length.

[0147] Due to the action of the knock cam mechanism in this embodiment based on the above-described knock operation, the handwriting input cartridge 5 is locked in a state in which the nib portion protrudes the specified protrusion length Lp from the opening 2a of the nib-side housing portion 21. Then, in the state shown in Figure 16(C), the contracted elastic displacement portion 54 of the handwriting input cartridge 5 returns to its original length, and the electronic pen 1 enters a state for use in handwriting input in which the nib portion of the handwriting input cartridge 5 is extended by the specified protrusion length Lp, completing the extension of the nib portion of the handwriting input cartridge 5 by the knock operation.

[0148] As is clear from the above description, the axial length of movement of the pen tip side of the handwriting input cartridge 5 during a knock operation is smaller than the axial stroke length (corresponding to the axial movement distance of the front shaft portion 43) of the knock cam mechanism when the knock operation is performed to cause the pen tip side of the handwriting input cartridge 5 to protrude from the opening 2a of the pen tip side housing portion 21 of the pen housing 2. That is, the pen tip side of the handwriting input cartridge 5 moves an amount equal to the amount of depression of the knock operation portion Nk until the protruding portion 57 abuts the step portion 21s of the pen tip side housing portion 21, but does not move any further. Then, when pressure (load) that resists the coil spring 542 of the elastic displacement portion 54 is applied to the knock operation portion Nk, the elastic displacement portion 54 of the handwriting input cartridge 5 changes its axial length. This displacement in the length of the elastic displacement portion 54 constitutes part of the stroke required during the knock operation.

[0149] In the state of use of the handwriting input cartridge 5 shown in Figure 16 (C), when the user applies writing pressure by bringing the tip of the pen tip core body 51 into contact with the input surface of the position detection sensor, the elastic displacement portion 54 is insensitive to the writing pressure, so the writing pressure detection portion 55 accurately detects the writing pressure applied to the tip of the core body 51.

[0150] When the pen tip of the handwriting input cartridge 5 is extended from the opening 2a of the pen housing 2 (pen tip side housing portion 21), if an impact load is applied to the pen tip side, for example by accidentally dropping the electronic pen 1, the impact load is absorbed by the elastic displacement of the elastic displacement portion 54, thereby preventing damage to the handwriting input cartridge 5. In other words, the elastic displacement portion 54 acts as a so-called shock absorber. It also acts as a shock absorber when an impact load is applied to the rear end cap member 44 side.

[0151] 16C , to return the pen tip portion of the handwriting input cartridge 5 to the state of FIG. 15A in which the pen tip portion is housed within the pen tip-side housing 21, in the electronic pen 1 of this embodiment, a pressure (load) that resists the elastic displacement force of the coil spring 542 of the elastic displacement portion 54 of the handwriting input cartridge 5 must be applied to the knock operation portion Nk. This is because, in the electronic pen 1 of this embodiment, the protruding portion 57 of the handwriting input cartridge 5 and the step portion 21s in the pen tip-side housing 21 are engaged with each other, and therefore, in order to release the engagement between the wing portion 43a of the front shaft portion 43 and the locking portion 41f of the small diameter portion 41b of the knock case 41, the elastic displacement portion 54 must be contracted. Then, by following the reverse procedure of the procedure for extending the tip of the writing input cartridge described above, the tip of the writing input cartridge 5 returns to the state shown in Figure 15 (A) where it is stored within the pen tip side housing portion 21.

[0152] 16C , when rear end cap member 44 is pushed in by applying pressure (load) to knock operation portion Nk against the elastic displacement force of coil spring 542 of elastic displacement portion 54, step portion 21s of pen tip side housing portion 21 and protruding portion 57 of handwriting input cartridge 5 are engaged, so that the protrusion length on the pen tip side of handwriting input cartridge 5 remains the specified protrusion length Lp, but elastic displacement portion 54 of handwriting input cartridge 5 contracts axially, and front shaft portion 43 is displaced toward gear portion 45. In response to this, blade portion 43a of front shaft portion 43 disengages from locking portion 41f of small diameter portion 41b of knock case 41, and the tip end of front shaft portion 43 meshes with gear portion 45, causing front shaft portion 43 to rotate.

[0153] Then, due to the elastic return force of the coil spring 542 of the elastic displacement portion 54 and the elastic return force of the coil spring 47 for elastic return, the front shaft portion 43 moves away from the gear portion 45 while rotating, returning to the state shown in Figure 15 (A) in which the wing portion 43a of the front shaft portion 43 fits into the groove portion 41c of the knock case portion 41, and the tip portion of the writing input cartridge 5 returns to a state in which it is stored within the pen tip side housing portion 21.

[0154] [Effects of the electronic pen 1 of the embodiment] As described above, in the electronic pen 1 of this embodiment, when the electronic pen 1 is knocked, the step portion 21s of the pen tip side housing portion 21 engages with the protrusion portion 57 of the handwriting input cartridge 5, and the pen tip side of the handwriting input cartridge 5 is maintained in a state where it does not protrude more than the specified protrusion length Lp, while the elastic displacement of the elastic displacement portion 54 enables the knock cam mechanism portion to extend and return the pen tip portion of the handwriting input cartridge 5.

[0155] Therefore, the protruding portion 57 prevents the writing input cartridge 5, which is extended by the knock operation, from displacing in a direction perpendicular to the axial direction. This also prevents the coil 521, which is an example of a part on the pen tip side of the writing input cartridge 5 that should not come into contact with the inner wall surface of the pen tip side housing portion 21, from coming into contact with the inner wall surface of the pen tip side housing portion 21.

[0156] Furthermore, in the electronic pen 1 of this embodiment, when writing input is performed by protruding the tip of the writing input cartridge 5 shown in Figure 16 (C) from the opening 2a of the pen tip side housing portion 21, the knock cam mechanism portion is configured not to operate unless pressure (load) that resists the elastic displacement force of the coil spring 542 of the elastic displacement portion 54 is applied to the knock operation portion Nk to push in the rear end cap member 44.

[0157] Therefore, as shown in Figure 16 (C), when writing is being performed with the tip of the writing input cartridge 5 protruding from the opening 2a of the pen tip side housing part 21, the user can hold the electronic pen 1 in a position where the tip side and the rear end side are reversed, and contact the rear end cap member 44 side of the electronic pen 1 with the position detection sensor to issue an erase command in a convenient manner.

[0158] In other words, when the rear end cap member 44 side is pressed against the position detection sensor to perform electronic erasure using the erase cartridge 6 of the electronic pen 1, no knocking action is performed by the knock cam mechanism unless a pressure (load) greater than the elastic displacement force of the coil spring 542 of the elastic displacement portion 54 of the handwriting input cartridge 5 is applied, so that an erase command can be given with strong pressure applied, making it easy to use.

[0159] Moreover, in the electronic pen 1 of this embodiment, the front shaft portion 43 and the rear shaft portion 42 are coupled together, and the rear cap member 44 including the knock operation portion Nk is coupled to the rear shaft portion 42, so that the rear cap member 44 including the knock operation portion Nk is held in the position shown in Figure 16(C). In other words, the rear cap member 44 does not move freely axially between the dotted line position and the solid line position, as does the knock rod 12PR of the knock ballpoint pen in the state shown in Figure 14(D). Therefore, the poor usability of the knock ballpoint pen described above can be improved.

[0160] Furthermore, as described above, the electronic pen 1 of this embodiment can be assembled by sequentially fitting multiple parts in the axial direction, and can also be easily disassembled in the reverse order. Therefore, each part can be replaced, making it economical.

[0161] [Other embodiments or variations] In the electronic pen 1 of the above-described embodiment, the front shaft portion 43 constituting the rotor portion and the rear end shaft portion 42 constituting the knock rod are connected, but they do not have to be connected as long as the rear end shaft portion 42 can press and move the front shaft portion 43 in the axial direction.

[0162] Furthermore, in the above embodiment, a gear portion 45 is used to rotate the front shaft portion 43, which is an example of a rotor portion, but it goes without saying that the configuration for rotating the rotor portion is not limited to this example.

[0163] Furthermore, in the above-described embodiment, in order to configure the knock cam mechanism so that it will not operate when using the erase cartridge 6 of the electronic pen 1 unless a load greater than the load applied during a normal knock operation in the case of a conventional knock-type ballpoint pen or the like is applied, the coil spring 47 of the knock cam mechanism and the coil spring 542 of the elastic displacement portion 54 of the writing input cartridge 5 are used, and the protrusion portion 57 is engaged with the step portion 21s of the pen tip side housing portion 21, but the present invention is not limited to this configuration.

[0164] For example, by using a coil spring 47 of the knock cam mechanism that has the same elastic properties as the coil spring 542, removing the elastic displacement portion 54 from the writing input cartridge 5, and configuring it without the protrusion portion 57 and step portion 21s, it is possible to configure the knock cam mechanism so that when using the erase cartridge 6 of the electronic pen 1, a load greater than the load applied during a normal knock operation in the case of a conventional knock-type ballpoint pen, etc., will not operate.

[0165] In this case, however, a large load must also be applied when starting the knock operation, making the knock operation difficult. In this regard, the configuration of the electronic pen 1 of the above-described embodiment is advantageous in that, when starting the knock operation to extend the pen tip side of the writing input cartridge 5, only the coil spring 47 of the knock cam mechanism needs to be elastically displaced, and therefore operation of the knock cam mechanism can be started with a relatively light load.

[0166] In the above embodiment, the stopper portion on the inner wall surface of the pen tip side housing 21 that engages with the protruding portion 57 to prevent the handwriting input cartridge 5 from moving toward the pen tip side is configured as a step 21s formed by changing the diameter of the hollow portion of the pen tip side housing 21, but is not limited to such a step 21s and may be any portion that can engage with the protruding portion 57 to prevent the handwriting input cartridge 5 from moving toward the pen tip side. For example, the stopper portion may be configured as a protrusion that engages with all or part of the protruding portion 57 on the inner wall surface of the pen tip side housing 21 to prevent the handwriting input cartridge 5 from moving toward the pen tip side.

[0167] Furthermore, in the above-described embodiment, the protruding portion 57 provided on the handwriting input cartridge 5 protrudes in a direction perpendicular to the axial direction of the cartridge housing 53, but this is not limited to a perpendicular direction, and it may be in a direction intersecting the axial direction and engage with the step portion 21s of the pen tip side housing 21. In consideration of this case, when determining the formation positions of the step portion 21s and the protruding portion 57, the selection should be made based on the engagement position between the step portion 21s and the protruding portion 57.

[0168] Furthermore, in the above-described embodiment, the protrusion 57 is formed so as to protrude from angular ranges that are 180 degrees apart from each other on the outer periphery of the cartridge housing 53, but this is not limited to this, and it may be formed so as to protrude in three directions from angular ranges that are 120 degrees apart from each other, or a single protrusion may be formed over a specified angular range on the outer periphery of the cartridge housing 53.

[0169] Moreover, the protruding portion 57 may be formed around the entire circumference of the cartridge housing 53. Figure 17 shows an example in which a protruding portion is formed around the entire circumference of the cartridge housing 53, and in this example, the shape of the holder portion 531 of the cartridge housing 53 is devised to form the protruding portion.

[0170] Fig. 17(A) is an enlarged view of the coupling side of the holder part 531A of the cartridge housing 53A in this example with the signal transmitting member 52 made of the coil 521 wound around the ferrite core 522. Fig. 17(B) is an enlarged perspective view of the signal transmitting member 52 made of the coil 521 wound around the ferrite core 522 and the holder part 531A of the cartridge housing 53A.

[0171] 17 , the holder portion 531A of the cartridge housing 53A has an outer diameter equal to the outer diameter R0 of the protective cover portion 532 at the position where it is coupled to the nib-side end of the protective cover portion 532. The holder portion 531A has a protruding portion 57A whose outer diameter gradually increases from the outer diameter R0 at the position where it is coupled to the protective cover portion 532 toward the nib side, and whose maximum outer diameter is R6 that is approximately equal to or slightly smaller than the inner diameter R5 of the hollow portion 21e of the nib-side housing 21. In the example of FIG. 17 , a tip portion 531Aa is formed further toward the nib than the protruding portion 57A, and whose outer diameter is equal to the outer diameter R0 of the protective cover portion 532.

[0172] 17A and 17B, a step is formed at the boundary between the pen tip side end of the protruding portion 57A and the tip portion 531Aa, and the end surface 57Aa of the protruding portion 57A constituting this step engages with the step 21s of the pen tip side housing 21. Note that the holder portion 531A may be formed to have only the protruding portion 57A without providing the tip portion 531Aa, and the end surface 57Aa of the protruding portion 57A may be configured to engage with the step 21s, which is an example of a stopper portion, on the inner wall surface of the pen tip side housing 21.

[0173] 17A and 17B, in this embodiment, a recess 57Ab is provided at a predetermined angular position in the circumferential direction in the protruding portion 57A of the holder portion 531A. Meanwhile, in this example, a protrusion that engages with the recess 57Ab is formed at a predetermined angular position in the circumferential direction on the inner wall surface near the step portion 21s of the pen tip side housing portion 21, and the engagement of the protrusion of the pen tip side housing portion 21 with the recess 57Ab prevents the handwriting input cartridge 5 from rotating about the axial direction. In other words, the recess 57Ab is used to prevent the handwriting input cartridge 5 from rotating.

[0174] 17(B), a recessed groove 57Ac is formed along the axial direction at a predetermined angular position in the circumferential direction on the outer peripheral surface of the protruding portion 57A of the holder portion 531A. Also, in this example, as shown in FIG. 17(B), lead portions 521a and 521b at both ends of the coil 521 are housed in this recessed groove 57Ac and are led into the protective cover portion 532. A circuit board held by the holder portion 531A is located inside the protective cover portion 532, and the lead portions 521a and 521b of the coil 521 are connected to a capacitor disposed on this circuit board to form a resonant circuit.

[0175] In the above-described embodiment, the elastic displacement portion 54 of the handwriting input cartridge 5 is provided on the rear end side of the cartridge housing 53, 53A, but it may be provided in the middle of the cartridge housing 53. For example, the protective cover portion 532 of the cartridge housing 53, 53A may be divided into two, and the elastic displacement portion 54 may be provided in the middle of the two divided protective cover portions 532.

[0176] The pen tip of the first position indicating unit for handwriting input may be configured to leave handwriting marks on a writing medium such as paper, and an erasing function unit for erasing handwriting marks on the writing medium may be provided at the tip of the rear knocking unit NK. For example, the core body of the handwriting input cartridge 5 constituting the first position indicating unit may be made of a material containing graphite to leave handwriting marks on a writing medium such as paper, and an eraser member for erasing handwriting marks made of graphite may be provided at the tip of the rear knocking unit NK.

[0177] In the above-described embodiment, the first position indication unit is configured for handwriting input, and the second position indication unit is configured for erasure, but both the first position indication unit and the second position indication unit may be configured for handwriting input.

[0178] Furthermore, in the above-described embodiment, the first position indication unit and the second position indication unit are configured as electronic pen cartridges, but either one or both of them may be configured as something other than an electronic pen cartridge.

[0179] Furthermore, in the above-described embodiment, the electronic pen has a special configuration in which it can be assembled by sequentially connecting multiple parts, and the assembled product can be easily separated into multiple parts by disconnecting the connections in the reverse order of assembly, but it goes without saying that the electronic pen is not limited to such a configuration.

[0180] Furthermore, while the above-described embodiment has been described with reference to an electronic pen of the electromagnetic induction type, the present invention is not limited to the electromagnetic induction type and can be similarly applied to an electronic pen of the capacitance type, such as an active capacitance type. Note that even in the case of an electronic pen of the capacitance type, the first position indication unit and / or the second position indication unit can be configured as an electronic pen cartridge.

[0181] 1...electronic pen, 2...pen housing, 2a...opening, 3...electronic pen main body module, 4...electronic pen main body constituent part, 5...cartridge for writing input, 6...erasing cartridge, 21...pen tip side housing part, 22...rear end side housing part, 21s...step part, 41...knock case part, 42...rear end side shaft part, 42...front shaft part, 44...rear end cap member, 45...gear part, 46...gear holder part, 47...coil spring, 48...spacer 101AS, 102AS, 103AS, 104AS... Assembly parts, 521, 621... Coil, 522, 622... Ferrite core, 531... Holder part, 532... Protective cover part, 541... Rod-shaped member, 542... Coil spring, 543... Fitting convex part

Claims

1. An electronic pen comprising: a cylindrical pen housing; a first position indicating unit disposed at one axial end of said pen housing; a second position indicating unit disposed at the other axial end of said pen housing; and a knock cam mechanism that is driven by an axial load applied from the other axial end, wherein said first position indicating unit is disposed so that its tip end that indicates a position can be extended and retracted from an opening at said one axial end of said pen housing by said knock cam mechanism; said second position indicating unit is disposed so that its tip end that indicates a position is at said other axial end, and wherein said electronic pen comprises an elastic member that causes said tip end of said first position indicating unit to be extended and retracted from said opening by said knock cam mechanism when a pressure greater than the pressure applied to the tip end of said second position indicating unit when said second position indicating unit is in use is applied to said other axial end.

2. The electronic pen described in claim 1, characterized in that the knock cam mechanism is provided with an elastic return member for returning the tip side of the first position indicating part from a state in which it protrudes from the opening to a state in which it is stored within the pen housing, and the elastic member is composed of the elastic return member.

3. The electronic pen described in claim 1, characterized in that the knock cam mechanism comprises a cam body, a knock bar, and a rotor, the knock bar and rotor being connected in the axial direction within the pen housing, the first position indicating part being engaged with the rotor on the side opposite to the tip in the axial direction, and the second position indicating part being disposed on the knock bar.

4. The electronic pen described in claim 1, wherein the knock cam mechanism comprises an elastic return member for returning the tip side of the first position indication part from a state in which it protrudes from the opening to a state in which it is housed within the pen housing; the first position indication part comprises an elastic displacement part that is insensitive to the range of pressure applied to the tip side during use, and that, when a load greater than the range of pressure is applied, elastically contracts and displaces the axial length of the first position indication part or the second position indication part in accordance with the applied load; a protrusion part that protrudes in a direction intersecting the axial direction is formed at a predetermined position in the axial direction of the first position indication part; and a stopper part that engages with the protrusion part and prevents movement of the position indication part towards the tip side within the pen housing when the tip side of the first position indication part is exposed to the outside through the opening of the pen housing; and the elastic member is composed of the elastic return member and the elastic displacement part.

5. The electronic pen according to claim 4, wherein the knock cam mechanism comprises a cam body, a knock bar, and a rotor, the knock bar and rotor being axially connected within the pen housing, the first position indicating part being engaged with the rotor on the side opposite to the tip in the axial direction, and the second position indicating part being disposed on the knock bar.

6. The electronic pen described in claim 5, characterized in that the elastic return member is disposed between the rotor and a predetermined position in the axial direction in the hollow portion of the pen housing in which the first position indicating portion is housed.

7. The electronic pen according to claim 4, wherein the elastic displacement portion is provided on the opposite side of the tip side of the first position indication portion in the axial direction.

8. The electronic pen described in claim 5, characterized in that the elastic displacement portion is provided at an end opposite the tip side in the axial direction with respect to the first position indication portion, and the elastic displacement portion is provided with a fitting portion that fits into and engages with the rotor portion.

9. The electronic pen described in claim 4, characterized in that the extension portion is arranged so that the length in the axial direction from the tip position of the tip side of the first position indicating portion to the part of the extension portion that engages with the step portion is the length in the axial direction from the tip position of the tip side of the pen housing to the step portion plus the axial length that is set so that the tip side of the first position indicating portion should protrude from the opening of the pen housing when the electronic pen is in use.

10. An electronic pen as described in claim 4, characterized in that the axial length of movement of the tip of the first position indicating portion during the knock operation is smaller than the length of the axial stroke during the knock operation of the knock cam mechanism portion when the tip side of the first position indicating portion is caused to protrude from the first opening of the pen housing.

11. An electronic pen as described in claim 4, characterized in that when the tip side of the first position indication portion is caused to protrude from the opening of the pen housing, the knock cam mechanism portion operates due to pressure resisting the elastic displacement force of the elastic return member until the protruding portion of the first position indication portion engages with the stopper portion of the pen housing, and after the protruding portion of the first position indication portion engages with the stopper portion of the pen housing, the knock cam mechanism portion operates due to pressure resisting the elastic displacement force of the elastic displacement portion.

12. The electronic pen described in claim 4, characterized in that the rotor portion moves in the axial direction in response to movement of the first position indicating portion of the knock bar portion toward the tip side and engages with the cam piece of the cam main body portion, and at a predetermined position in the axial direction within the pen housing that engages with the end portion of the first position indicating portion of the rotor portion toward the tip side, a gear portion is provided that rotates the rotor portion by a predetermined angle when the rotor portion engages.

13. The electronic pen described in claim 1, characterized in that the knock cam mechanism comprises a cam main body, a knock rod, and a rotor, the knock rod having a cylindrical body, and at least the portion of the second position indicating portion opposite the tip side is housed within the cylindrical body.

14. The electronic pen according to claim 13, wherein the tip side of the second position indicating portion is covered with a cylindrical portion.

15. The electronic pen according to claim 1, wherein the tip side of the second position indicating portion is covered with a cap-like member.

16. The electronic pen according to claim 1, wherein the first position indication unit is used for writing input or drawing input, and the second position indication unit is used for erasing writing input or drawing input by the first position indication unit.

17. The electronic pen according to claim 1, wherein the first position indication unit and the second position indication unit are configured using an electromagnetic induction method.

18. The electronic pen according to claim 1, wherein the first position indication unit and the second position indication unit have an active capacitance type configuration.

19. The electronic pen described in claim 1, characterized in that the first position indication unit is configured as a cartridge modularizing an electronic circuit arranged in a cylindrical housing and an interaction unit that interacts with the position detection sensor.

20. The electronic pen described in claim 1, characterized in that the second position indication unit is configured as a cartridge modularizing an electronic circuit arranged in a cylindrical housing and an interaction unit that interacts with the position detection sensor.

21. The electronic pen according to claim 4, wherein the stopper portion is configured as a step portion formed on the inner wall surface of the pen housing.