Knock-type writing implement

Abstract

A mechanical pencil 3 comprises: a barrel 4; a knock member 9 provided with an operation part 9a; a mechanical pencil mechanism 10 having a writing lead and configured to be brought into a writing state as a result of a knock operation of the operation part 9a; an electronic component 20 including a pressure sensor 24 that detects writing pressure applied to the writing lead; and a transmission member 50 configured to cooperate with the mechanical pencil mechanism 10 to transmit the writing pressure received by the writing lead to the pressure sensor 24. The writing lead is disposed along a central axis of the mechanical pencil 3, and the pressure sensor 24 is disposed eccentrically with respect to the central axis.

Description

Knock-type writing implement

[0001] The present invention relates to a knock-type writing instrument.

[0002] A mechanical pencil is known that includes a mechanical pencil mechanism with a lead case that can store a writing lead, and electronic components including a power source and a writing pressure sensor (see, for example, Patent Document 1). The electronic components perform information processing related to data in response to user operations, for example.

[0003] The mechanical pencil mechanism according to the embodiment described in Patent Document 1 is a simple and slim mechanical pencil mechanism used in a multi-lead writing instrument with multiple writing elements. Specifically, this mechanical pencil mechanism is a type of mechanism known as a "Sharp Unit M Type" for mechanical pencils as defined in JIS S 6013:2020, and for convenience, will be referred to as a "multi-lead mechanical pencil mechanism." Note that the mechanical pencil mechanism in a typical mechanical pencil, which is a single-element writing instrument rather than a multi-lead writing instrument, is a type of mechanism known as a "Knock Type F Type" in the JIS standard, and for convenience, will be referred to as a "single-element mechanical pencil mechanism."

[0004] Both the multi-core mechanical pencil mechanism and the single-action mechanical pencil mechanism have a chuck unit that includes a chuck body member that grips the lead and a fastener that can surround the front end of the chuck body member, allowing the chuck body member to grip and release the lead by moving back and forth. The multi-core mechanical pencil mechanism is configured so that when writing pressure is applied to the lead during writing, it moves back slightly, causing both the chuck body member and the fastener to move back as the lead moves back. On the other hand, the single-action mechanical pencil mechanism moves back slightly when writing pressure is applied to the lead during writing, causing the chuck body member to move back relative to the fastener as the lead moves back. As a result, the single-action mechanical pencil mechanism is configured so that the chuck unit grips the lead more tightly when writing pressure is applied.

[0005] The mechanical pencil described in Patent Document 1 has components other than the mechanical pencil mechanism, such as multiple cylindrical members, in order to efficiently accommodate electronic components including a writing pressure sensor within the barrel and to enable the writing pressure sensor to function effectively.

[0006] Japanese Patent Application Laid-Open No. 2021-49681

[0007] Therefore, the mechanical pencil described in Patent Document 1 has a large number of parts other than the mechanical pencil mechanism and a complex structure, which results in the problem of time-consuming and costly assembly work. Furthermore, due to its simple configuration, the multi-lead mechanical pencil mechanism prevents unnecessary retraction of the writing lead by providing unevenness on the gripping surface of the chuck body member. Therefore, there is also the problem that the multi-lead mechanical pencil mechanism places a greater load on the writing lead than a single-lead mechanical pencil mechanism, making the writing lead more likely to break.

[0008] An object of the present invention is to provide a mechanical pencil equipped with electronic components that has a simpler structure.

[0009] According to one aspect of the present invention, there is provided a knock-type writing instrument comprising a barrel, a knock member having an operating unit, a writing body mechanism having a writing body and configured to enter a writing state by knocking the operating unit, an electronic component including a writing pressure sensor that detects the writing pressure applied to the writing body, and a transmission member that cooperates with the writing body mechanism and is configured to transmit the writing pressure applied to the writing body to the writing pressure sensor, wherein the writing body is arranged along the central axis of the knock-type writing instrument and the writing pressure sensor is arranged eccentrically with respect to the central axis.

[0010] The writing mechanism may include a writing lead, a chuck unit including a chuck body member that grips the writing lead and a fastener that can surround the front end of the chuck body member and can grip and release the writing lead by moving the chuck body member back and forth, and may be configured so that the chuck body member retracts relative to the fastener when the writing lead is retracted. The writing mechanism may include a rotational drive mechanism with a rotor, and the rotational drive mechanism may be configured to rotate the rotor in one direction in response to an axial retraction movement due to writing pressure applied to the writing lead gripped by the chuck unit and an axial advancement movement due to the release of writing pressure. The rotational drive mechanism may retract due to writing pressure applied to the writing lead, and the writing pressure sensor may detect the writing pressure when the rotational drive mechanism retracts. Part or all of the operating unit may be an erasing unit that can erase handwriting made with the writing lead.

[0011] According to the aspects of the present invention, a common effect is achieved in that a mechanical pencil having an electronic component and having a simpler structure is provided.

[0012] FIG. 1 is a side view of a mechanical pencil, which is a knock-type writing instrument according to a first embodiment of the present invention. FIG. 2 is another side view of the mechanical pencil of FIG. 1. FIG. 3 is a cross-sectional view of the mechanical pencil taken along line A-A in FIG. 1. FIG. 4 is a cross-sectional view of the mechanical pencil taken along line B-B in FIG. 2. FIG. 5 is an exploded perspective view of the mechanical pencil of FIG. 1. FIG. 6 is a perspective view of the mechanical pencil of FIG. 1 with the barrel removed. FIG. 7 is a functional block diagram of the barrel 4. FIG. 8 is an enlarged cross-sectional view of the front half of the mechanical pencil of FIG. 1. FIG. 9 is a schematic diagram illustrating the rotational drive of the rotor of the rotation drive mechanism. FIG. 10 is a schematic diagram illustrating the rotational drive of the rotor, following FIG. 9. FIG. 11 is a vertical cross-sectional view of a knock member. FIG. 12 is a perspective view of a transmission member. FIG. 13 is a vertical cross-sectional view of the transmission member. FIG. 14 is a side view of a mechanical pencil, which is a knock-type writing instrument according to a second embodiment of the present invention. FIG. 15 is another side view of the mechanical pencil of FIG. 14. FIG. 16 is a cross-sectional view of the mechanical pencil taken along line C-C in FIG. 14. FIG. 17 is a cross-sectional view of the mechanical pencil taken along line D-D in FIG. 15. FIG. 18 is an exploded perspective view of the mechanical pencil in FIG. 14. FIG. 19 is a perspective view of the mechanical pencil in FIG. 14 with the barrel removed. FIG. 20 is a perspective view of the knock member. FIG. 21 is a perspective view of the transmission member. FIG. 22 is a vertical cross-sectional view of the transmission member. FIG. 23 is a perspective view of the connecting member. FIG. 24 is a perspective view of the fixing member. FIG. 25 is an enlarged cross-sectional view of the central portion of the mechanical pencil in FIG. 14. FIG. 26 is a vertical cross-sectional view of a ballpoint pencil which is a knock-type writing instrument according to a third embodiment of the present invention. FIG. 27 is another vertical cross-sectional view of the ballpoint pen in FIG. 26. FIG. 28 is an exploded perspective view of the ballpoint pen in FIG. 26. FIG. 29 is an enlarged cross-sectional view of the central portion of the ballpoint pen in FIG. 26. FIG. 30 is a perspective view of the inner barrel.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Corresponding components throughout the drawings are designated by common reference numerals.

[0014] FIG. 1 is a side view of a mechanical pencil 3, which is a knock-type writing instrument according to a first embodiment of the present invention; FIG. 2 is another side view of the mechanical pencil 3 of FIG. 1; FIG. 3 is a cross-sectional view of the mechanical pencil 3 taken along line A-A in FIG. 1; FIG. 4 is a cross-sectional view of the mechanical pencil 3 taken along line B-B in FIG. 2; FIG. 5 is an exploded perspective view of the mechanical pencil 3 of FIG. 1; and FIG. 6 is a perspective view of the mechanical pencil 3 of FIG. 1 with the barrel 4 removed.

[0015] The mechanical pencil 3 and the communication terminal 2 constitute a communication system 1. The communication terminal 2 is an information processing device such as a mobile phone, a smartphone, a PC (Personal Computer), a tablet terminal, or a portable game console that is owned by a user of the mechanical pencil 3. The communication terminal 2 is an example of a communication device external to the mechanical pencil 3.

[0016] In response to detecting the user's action, the mechanical pencil 3 transmits a signal to the communication terminal 2 to initiate communication with the communication terminal 2. The predetermined action is, for example, the application of writing pressure to the writing lead as a writing body through the writing action, or a knocking operation on the mechanical pencil 3 to advance the writing lead. The mechanical pencil 3 can collect information related to the writing action and transmit it to the communication terminal 2 until the series of writing actions is completed. The communication terminal 2 can perform predetermined information processing using the information related to the writing action to generate information to assist the user in writing. The information to assist the user in writing is, for example, digital data indicating the characters written by the user. In this case, the predetermined information processing is processing to generate digital data indicating the characters written by the user based on the information related to the writing action.

[0017] The mechanical pencil 3 includes a barrel 4 having a cylindrical overall shape and including a front shaft 5 and a rear shaft 6, a tapered tip member 7 that fits onto the front end of the front shaft 5, a tail plug 8 that fits onto the rear end of the rear shaft 6, and a knock member 9 with an operating portion 9a that protrudes from the rear end of the barrel 4 via the tail plug 8. The tip member 7 may also be referred to as the barrel 4. The mechanical pencil 3 is configured so that a writing lead (not shown) protrudes from the tip of the barrel 4. In this specification, the writing lead side in the axial direction of the mechanical pencil 3 is defined as the "front" side, and the side opposite the writing lead side is defined as the "rear" side. In describing each component, the "front" side and "rear" side are defined based on the assembled state.

[0018] As shown in Figure 5, the inner surface of the front end of front barrel 5 is provided with a female threaded portion 5a that can be threadedly engaged with a male threaded portion 7a provided at the rear end of tip member 7. An insertion portion 5b is provided at the rear end of front barrel 5. The front end of front barrel 5 has a circular outer shape, while the rear end of front barrel 5 has a rounded rectangular outer shape, with the outer shape changing continuously from the circular front end to the rounded rectangular rear end. Accordingly, the outer surface of front barrel 5 is provided with a pair of opposing flat portions 5c. A curved surface continuously connected between the pair of flat portions 5c is provided with a pair of recesses 5d extending in the axial direction. A pair of mating protrusions 5e extending in the axial direction is provided on the outer surface of insertion portion 5b, which is located on the extension of each of the flat portions 5c.

[0019] The rear shaft 6 has a generally rounded rectangular outer shape. The insertion portion 5b of the front shaft 5 is inserted into the interior of the front end of the rear shaft 6. The front shaft 5 and rear shaft 6 are assembled by the fitting protrusion 5e of the insertion portion 5b engaging with the inner surface of the front end of the rear shaft 6. A pair of opposing flat portions 6a is provided on the outer surface of the rear shaft 6. When the front shaft 5 and rear shaft 6 are assembled, the flat portion 5c of the front shaft 5 and the flat portion 6a of the rear shaft 6 are formed to be flush. The user can securely grip the mechanical pencil 3 by placing their fingers on the flat portion 5c of the front shaft 5, the flat portion 6a of the rear shaft 6, and the recess 5d of the front shaft 5.

[0020] The tail plug 8 has a fitting portion 8a having the same external shape as the insertion portion 5b of the front barrel 5, and a fitting protrusion 8b having the same shape as the fitting protrusion 5e of the front barrel 5. The fitting portion 8a of the tail plug 8 is inserted into the interior of the rear end of the rear barrel 6. The fitting protrusion 8b of the fitting portion 8a engages with the inner surface of the rear end of the rear barrel 6, thereby assembling the rear barrel 6 and the tail plug 8. The tail plug 8 is provided with a through-hole 8c through which the operating portion 9a of the knock member 9 passes.

[0021] The mechanical pencil mechanism 10 and the electronic component 20 are arranged in series within the barrel 4. That is, the mechanical pencil mechanism 10 is arranged further forward within the barrel 4, and the electronic component 20 is arranged further rearward within the barrel 4.

[0022] First, the electronic component 20 will be described. The electronic component 20 includes an electronic board 21, a power source 22 that is a secondary battery, a charging unit 23, and a pressure sensor 24. The electronic board 21 is supplied with current from the power source 22. The charging unit 23 is configured to charge the power source 22. The charging unit 23 includes a connection unit 23a for connecting terminals and a power supply circuit for supplying current from the connection unit to the power source 22 to charge the power source 22. The power source 22 can be charged by removing the tail plug 8, exposing the charging unit 23, and connecting a terminal of another power source to the connection unit 23a. The connection unit 23a is configured to be connectable to a terminal conforming to a standard such as USB-C (Universal Serial Bus Type C).

[0023] The pressure sensor 24 serves as a writing pressure sensor for detecting the writing pressure applied to the writing lead. The pressure sensor 24 is a pressure sensor that has a strain gauge that deforms in response to pressure applied to its detection surface and a resistance element, such as a piezoresistor or conductive ink, arranged on the strain gauge. The pressure sensor 24 detects pressure by detecting changes in resistance value due to deformation of the strain gauge. The pressure sensor 24 is arranged on the electronic board 21 so that its detection surface is perpendicular to the axial direction of the barrel 4. In other words, the pressure sensor 24 is arranged on the front end surface of the electronic board 21. By fixing the electronic board 21 to the barrel 4 and restricting its rearward movement, the pressure sensor 24 arranged on the electronic board 21 can accurately detect pressure.

[0024] Various sensors 61, including a pressure sensor 24, are arranged on the electronic board 21. The other sensors 61 are, for example, magnetic field sensors and inertial sensors. The magnetic field sensors are sensors that detect magnetic fields, such as Hall sensors. The inertial sensors are sensors that detect three-axis acceleration and angular velocity applied to the barrel 4, and include, for example, acceleration sensors and gyro sensors. The sensors 61 can generate information about the operation of the barrel 4 on a regular or irregular basis.

[0025] 7 is a functional block diagram of the barrel 4. The barrel 4, specifically the electronic board 21, is provided with a sensor 61, a switch 62 for receiving user operations, a notification unit 63 for issuing predetermined notifications to the user, a memory unit 64, a communication unit 65, and a processing unit 70.

[0026] The storage unit 64 is configured to store programs and data, and includes, for example, a semiconductor memory. The storage unit 64 stores programs such as an operating system program, driver programs, and application programs used in processing by the processing unit 70. Programs are installed into the storage unit 64 from computer-readable, non-transitory, portable storage media such as a CD-ROM (Compact Disc Read Only Memory) or a DVD-ROM (Digital Versatile Disc Read Only Memory).

[0027] The communication unit 65 is a component that enables the mechanical pencil 3 to communicate with other devices such as the communication terminal 2, and includes a communication interface circuit. The communication interface circuit is an interface circuit for a short-range wireless communication method such as BLE (Bluetooth Low Energy) (registered trademark). The communication unit 65 transmits data supplied from the processing unit 70 to other devices, and also supplies data transmitted from other devices to the processing unit 70.

[0028] The processing unit 70 is configured to comprehensively control the operation of the mechanical pencil 3 and includes one or more processors and their peripheral circuits. The processing unit 70 includes, for example, a CPU (Central Processing Unit). The processing unit 70 may also include a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. The processing unit 70 controls the operation of each component and executes various processes so that the various processes of the mechanical pencil 3 are executed in an appropriate order based on the programs stored in the storage unit 64.

[0029] The processing unit 70 has a determination unit 71, a transmission unit 72, a notification control unit 73, an acquisition unit 74, and a correction unit 75. Each of these units is a functional module realized by the processing unit 70 executing a program. Each of these units may be implemented in the barrel 4 as a dedicated processing circuit.

[0030] Next, the mechanical pencil mechanism 10 will be described. Figure 8 is an enlarged cross-sectional view of the front half of the mechanical pencil 3 of Figure 1. The mechanical pencil mechanism 10 includes a slider 13 equipped with a tip pipe 11 and a retaining chuck 12 for guiding the lead, a relay member 14, a chuck unit 15, and a rotation drive mechanism 30. The slider 13 is cylindrical, with its outer diameter tapering in stages toward the front. The front end of the slider 13, together with the tip pipe 11, protrudes from the front end of the barrel 4, i.e., the front end of the tip member 7. Alternatively, only the tip pipe 11 may protrude from the front end of the barrel 4. A retaining chuck 12 with a through hole formed in the center is disposed within the slider 13 behind the tip pipe 11. The through hole of the retaining chuck 12 makes sliding contact with the outer surface of the lead, temporarily holding the lead.

[0031] A cylindrical relay member 14 is threadedly engaged with the rear end of the slider 13. A chuck unit 15 for gripping a writing lead and a lead case 16 are disposed inside the slider 13 and relay member 14. The chuck unit 15 includes a chuck main body member 17, a cylindrical chuck holding member 17a for gripping the rear end of the chuck main body member 17, and a cylindrical fastener 18 for surrounding the front end of the cylindrical chuck main body member 17. The outer surface of the fastener 18 is fitted to the inner surface of the front end of the relay member 14. The inner surface of the fastener 18 is formed into a conical surface whose inner diameter continuously decreases toward the rear. At least the front half of the chuck main body member 17 is divided into three chuck pieces along the axial direction, and a through hole for the writing lead is formed along the central axis. The chuck pieces are formed so that their front ends are spaced apart from each other. The lead case 16 is cylindrical and houses a writing lead. The rear end of the chuck holding member 17a is inserted into the front end of the lead case 16 and fitted therein.

[0032] A coil spring 19 is disposed to surround the chuck body member 17. The front end of the coil spring 19 is supported by a step formed on the inner surface of the relay member 14, and the rear end of the coil spring 19 abuts against the front end surface of the lead case 16. Therefore, the coil spring 19 biases the chuck body member 17 and the lead case 16 rearward. The chuck pieces of the chuck body member 17 biased rearward are housed within the fastener 18, causing their front ends to approach each other and maintaining a grip on the lead. Furthermore, when writing pressure is applied to the lead, the chuck body member 17 retracts relative to the fastener 18 and is housed further inside the fastener 18, and the lead is gripped by the chuck body member 17. This prevents the lead from retracting.

[0033] The slider 13, relay member 14, and chuck unit 15 are arranged inside the barrel 4 so as to be slidable in the axial direction and rotatable about the axis. The rear end of the relay member 14 is connected to the rotation drive mechanism 30. The lead case 16 passes through the interior of the relay member 14 and the rotation drive mechanism 30 and is spaced apart from the rotation drive mechanism 30. The rotation drive mechanism 30 is urged rearward by an axial spring 31. That is, the front end of the axial spring 31 is supported by the inner surface of the tip member 7, and the rear end of the axial spring 31 abuts against the front end face of the rotation drive mechanism 30. Therefore, the axial spring 31 urges the rotation drive mechanism 30 rearward.

[0034] The rotation drive mechanism 30 has a rotor 40 formed in a cylindrical shape, an upper cam forming member 41 which is a first cam forming member formed in a cylindrical shape, a lower cam forming member 42 which is a second cam forming member formed in a cylindrical shape, a cylinder member 43 formed in a cylindrical shape, a torque canceller 44 which is also formed in a cylindrical shape, and a coil-shaped cushion spring 45. The rotation drive mechanism 30 is a unit formed by integrating these members.

[0035] The outer surface of the rear end of the relay member 14 is fitted onto the inner surface of the front end of the rotor 40. This connects the relay member 14 to the rotation drive mechanism 30 as described above. The rotor 40 has a flange-shaped portion with a slightly larger diameter near its front end, with a first cam surface 40a formed on the rear end surface of that portion and a second cam surface 40b formed on the front end surface of that portion.

[0036] The upper cam forming member 41 rotatably surrounds the rotor 40 behind the first cam surface 40a of the rotor 40. The lower cam forming member 42 is fitted to the outer surface of the front end portion of the upper cam forming member 41. A first fixed cam surface 41a is formed on the front end surface of the upper cam forming member 41 that faces the first cam surface 40a of the rotor 40. A second fixed cam surface 42a is formed on the inner surface of the front end portion of the lower cam forming member 42 that faces the second cam surface 40b of the rotor 40.

[0037] A cylindrically shaped cylinder member 43 is fitted onto the outer surface of the rear end of the upper cam forming member 41. An insertion hole 43a is formed in the rear end of the cylinder member 43, through which the lead case 16 can be inserted. A cylindrically shaped torque canceller 44 that is movable in the axial direction is disposed within the cylinder member 43. A cushion spring 45 is disposed between the inner surface of the front end of the torque canceller 44 and the inner surface of the rear end of the cylinder member 43. The cushion spring 45 biases the rotor 40 forward via the torque canceller 44.

[0038] Here, the relay member 14 transmits the retreating and advancing movements (cushioning movements) of the writing lead based on the writing action to the rotation drive mechanism 30, i.e., the rotor 40, and also transmits the rotational movement of the rotor 40 in the rotation drive mechanism 30, which is generated by the cushioning movement, to the chuck unit 15, which is holding the writing lead. Therefore, the rotation of the relay member 14 also rotates the writing lead held by the chuck unit 15.

[0039] When not writing with the mechanical pencil 3, i.e., when no writing pressure is being applied to the writing lead, the rotor 40 is positioned forward by the biasing force of the cushion spring 45 via the torque canceller 44. Therefore, the second cam surface 40b of the rotor 40 abuts against the second fixed cam surface 42a and is in an engaged state. When writing with the mechanical pencil 3, i.e., when writing pressure is being applied to the writing lead, the chuck unit 15 moves backward against the biasing force of the cushion spring 45, and the rotor 40 also moves backward accordingly. Therefore, the first cam surface 40a of the rotor 40 abuts against the first fixed cam surface 41a and is in an engaged state. The writing lead and rotor 40 move forward, backward, or rotate together.

[0040] Fig. 9 is a schematic diagram illustrating the rotational drive of rotor 40 of rotation drive mechanism 30, and Fig. 10 is a schematic diagram illustrating the rotational drive of rotor 40 subsequent to Fig. 9. In Figs. 9 and 10, a first cam surface 40a having a continuous sawtooth shape along the circumferential direction is formed in an annular shape on the rear end surface, which is the upper surface of rotor 40, and a second cam surface 40b having a continuous sawtooth shape along the circumferential direction is formed in an annular shape on the front end surface, which is the lower surface of rotor 40.

[0041] A first fixed cam surface 41a having a continuous sawtooth shape along the circumferential direction is also formed on the annular end face of the upper cam forming member 41 that faces the first cam surface 40a of the rotor 40, and a second fixed cam surface 42a having a continuous sawtooth shape along the circumferential direction is also formed on the annular end face of the lower cam forming member 42 that faces the second cam surface 40b of the rotor 40. The cam surfaces of the first cam surface 40a and the second cam surface 40b formed on the rotor 40 and the cam surfaces of the first fixed cam surface 41a formed on the upper cam forming member 41 and the second fixed cam surface 42a formed on the lower cam forming member 42 are formed so that the pitches are substantially the same.

[0042] 9(A) shows the relationship between the advanced rotor 40, upper cam forming member 41, and lower cam forming member 42 when no writing pressure is applied to the writing lead. In this state, the second cam surface 40b formed on the rotor 40 abuts against the second fixed cam surface 42a of the lower cam forming member 42 due to the biasing force of the cushion spring 45. At this time, the first cam surface 40a of the rotor 40 and the first fixed cam surface 41a of the upper cam forming member 41 are set so as to be shifted by half a phase (half a pitch) with respect to one tooth of the cam in the axial direction.

[0043] 9(B) shows the initial state in which writing pressure is applied to the writing lead for writing with the mechanical pencil 3. In this state, the rotor 40 retracts by contracting the cushion spring 45 as the chuck unit 15 retracts. As a result, the rotor 40 moves toward the upper cam forming member 41 and abuts against the first fixed cam surface 41a.

[0044] 9(C) shows a state in which further writing pressure is applied to the writing lead, causing the rotor 40 to slide back while abutting against the first fixed cam surface 41a of the upper cam forming member 41. In other words, the rotor 40 receives a rotational drive equivalent to half the phase (half the pitch) of one tooth of the first cam surface 40a. In this state, the first cam surface 40a of the rotor 40 is engaged with the first fixed cam surface 41a of the upper cam forming member 41.

[0045] 9 and 10, the circle drawn in the center of the rotor 40 indicates the amount of rotational movement of the rotor 40. In the state shown in Fig. 9(C), the second cam surface 40b of the rotor 40 and the second fixed cam surface 42a of the lower cam forming member 42 are set to have a relationship in which they are shifted by half a phase (half a pitch) with respect to one tooth of the cam in the axial direction.

[0046] 10(D) shows the initial state after writing with the mechanical pencil 3 has finished and the writing pressure on the writing lead has been released. In this state, the rotor 40 moves forward due to the biasing force of the cushion spring 45. As a result, the rotor 40 moves toward the lower cam forming member 42 and abuts against the second fixed cam surface 42a.

[0047] 10(E) shows a state in which the rotor 40 advances while sliding against the second fixed cam surface 42a of the lower cam forming member 42 due to the biasing force of the cushion spring 45. That is, the rotor 40 is again subjected to a rotational drive force equivalent to half the phase (half the pitch) of one tooth of the second cam surface 40b. In this state, the second cam surface 40b of the rotor 40 is engaged with the second fixed cam surface 42a of the lower cam forming member 42.

[0048] 9 and 10, as the rotor 40 reciprocates in the axial direction, i.e., moves back and forth, when subjected to writing pressure, the rotor 40 is rotationally driven by a distance equivalent to one tooth (one pitch) of the first cam surface 40a and the second cam surface 40b, and the writing lead held therein is similarly rotationally driven via the chuck unit 15. Therefore, with one back and forth movement of the rotor 40 in the axial direction caused by writing, the rotor 40 undergoes a rotational movement corresponding to one tooth of the cam, and by repeating this process, the writing lead is sequentially rotationally driven. This prevents uneven wear of the writing lead as writing progresses, and prevents large changes in the thickness and darkness of the drawn lines.

[0049] The torque canceller 44, which pushes the rotor 40 forward by receiving the biasing force of the cushion spring 45, generates slippage between its front end face and the rear end face of the rotor 40, preventing the rotational motion of the rotor 40 from being transmitted to the cushion spring 45. In other words, the torque canceller 44 prevents the rotational motion of the rotor 40 from being transmitted to the cushion spring 45, thereby preventing the cushion spring 45 from twisting back (torque) which would hinder the rotational movement of the rotor 40.

[0050] As described above, the mechanical pencil mechanism 10 of the mechanical pencil 3 comprises a writing lead, a chuck unit 15 equipped with a chuck body member 17 that grips the writing lead and a fastener 18 that can surround the front end of the chuck body member 17, thereby being able to grip and release the grip of the writing lead, and a rotation drive mechanism 30 equipped with a rotor 40, and the rotation drive mechanism 30 is configured to rotate the rotor 40 in one direction in response to the axial backward movement caused by the writing pressure applied to the writing lead gripped by the chuck unit 15 and the axial forward movement caused by the release of the writing pressure.

[0051] FIG. 11 is a longitudinal cross-sectional view of the knock member 9. The knock member 9 has an operating portion 9a at its rear end and a receiving portion 9b at its front end. The operating portion 9a and receiving portion 9b are integrally connected by a connecting portion 9c in the shape of an elongated rectangular frame. The operating portion 9a is a cylindrical protrusion that protrudes rearward from the rear end of the connecting portion 9c. As described above, the operating portion 9a is configured to protrude rearward from the barrel 4 through the through-hole 8c of the tail plug 8 that fits into the rear end of the barrel 4. The receiving portion 9b is a cylindrical protrusion that protrudes forward from the rectangular front end surface of the connecting portion 9c. The receiving portion 9b is configured to receive the rear end of the lead case 16 that has passed through the rotation drive mechanism 30. The outer diameters of the operating portion 9a and receiving portion 9b are approximately the same as the thickness of the connecting portion 9c.

[0052] The knock member 9 is arranged parallel to the electronic component 20 within the barrel 4. The knock member 9 is arranged within the barrel 4 so that the central axis of the knock member 9 coincides with the central axis of the barrel 4. Within the barrel 4, an electronic board 21 is arranged on one side of the rectangular frame-shaped connecting portion 9c of the knock member 9. The power supply 22 is arranged on the electronic board 21 on the knock member 9 side and is surrounded by the connecting portion 9c of the knock member 9. The electronic board 21 of the electronic component 20 is fixed to the barrel 4. Therefore, the pressure sensor 24 arranged on the electronic board 21 is also fixed to the barrel 4. Therefore, the pressure sensor 24 is arranged eccentrically with respect to the central axis of the mechanical pencil 3. Adjacent knock members 9 are arranged to be movable back and forth relative to the barrel 4. The electronic components 20, i.e., the electronic board 21 and the power supply 22, are arranged so as not to obstruct the back and forth movement of the knock member 9.

[0053] The knock member 9 is biased rearward by a coil spring 32. The coil spring 32 is disposed so as to surround the lead case 16. The front end of the coil spring 32 is supported by the rear end surface of the rotation drive mechanism 30, specifically the rear end surface of the cylinder member 43, and the rear end of the coil spring 32 abuts against the annular front end surface of the receiving portion 9b of the knock member 9. Therefore, the coil spring 32 biases the knock member 9 rearward.

[0054] The lead case 16 advances when the knocking operation is performed, in which the knocking member 9, specifically the operating portion 9a, is pressed forward against the biasing force of the coil spring 32. As the lead case 16 advances, the chuck main body member 17 advances together with the fastener 18. As the fastener 18 advances, the relay member 14 advances together with the slider 13. The advancement of the slider 13 and relay member 14 is restricted by the outer surface of the slider 13 abutting against the inner surface of the tip member 7. If the knocking member 9 is further pressed forward in this state, the chuck main body member 17 is pushed forward and escapes from the fastener 18. As a result, the writing lead gripped by the chuck main body member 17 also advances, and the grip of the writing lead by the chuck main body member 17 is released. In short, the chuck unit 15 is capable of gripping and releasing the writing lead, thereby acting to feed the writing lead from the tip pipe 11.

[0055] When the pressure caused by the knock operation is released, the knock member 9 retracts and returns to its original position due to the biasing force of the coil spring 32. At this time, the chuck body member 17 retracts due to the biasing force of the coil spring 19. Meanwhile, the writing lead is held by the holding chuck 12 arranged in the slider 13. As a result, the writing lead is fed out from the tip pipe 11, so that a predetermined amount of writing lead can be fed out each time the knock operation is repeated. The chuck unit 15 may be another chuck unit, such as a ball chuck. The state in which the writing lead is protruded by the knock operation of the operating part 9a is called the writing state.

[0056] Fig. 12 is a perspective view of the transmission member 50, and Fig. 13 is a longitudinal cross-sectional view of the transmission member 50. The transmission member 50 is a cylindrical member. The transmission member 50 has a small diameter portion 51 and a large diameter portion 52 provided rearward of the small diameter portion 51. The transmission member 50 is provided with a through-hole 53 along the central axis. The large diameter portion 52 is provided with a pair of rectangular cutout portions 54 along the axial direction from the rear end surface to the vicinity of the small diameter portion 51. The pair of cutout portions 54 are arranged symmetrically with respect to the central axis.

[0057] As shown in Figure 8, small diameter portion 51 of transmission member 50 is inserted from the rear end of front axle 5. The outer diameter of small diameter portion 51 is formed slightly smaller than the inner diameter of front axle 5, while the outer diameter of large diameter portion 52 is formed larger than the inner diameter of front axle 5. This allows transmission member 50 to move back and forth relative to the rear end of front axle 5. The front end face of small diameter portion 51 abuts against rotation drive mechanism 30, specifically the rear end face of cylinder member 43, inside the rear end of front axle 5.

[0058] The width of the notch 54 of the transmission member 50 is formed slightly larger than the thickness of the knock member 9, specifically the thickness of the connecting portion 9c. As a result, the receiving portion 9b and the front end of the connecting portion 9c of the knock member 9 are disposed within the notch 54 of the transmission member 50. The coil spring 32 that urges the knock member 9 rearward is disposed within the through-hole 53 of the transmission member 50. In this state, the coil spring 32 urges the knock member 9 rearward as described above. As a result, the knock member 9 can be moved forward by the knock operation and rearward by the coil spring 32 without interference from the transmission member 50.

[0059] The contact surface 55 of the transmission member 50 is disposed so as to contact the pressure sensor 24 disposed on the electronic board 21. That is, within the barrel 4, the rotation drive mechanism 30 is urged rearward by the barrel spring 31, which in turn urges the transmission member 50 rearward, causing the contact surface 55 of the transmission member 50 to contact the opposing pressure sensor 24.

[0060] During a writing operation, when the writing lead retracts due to writing, the chuck body member 17 that grips the writing lead retracts relative to the fastener 18. Because the inner diameter of the inner surface of the fastener 18 decreases toward the rear, when the chuck body member 17 retracts relative to the fastener 18, the front ends of the three chuck pieces of the chuck body member 17 move closer to each other. This allows the writing lead to be gripped more firmly by the chuck body member 17.

[0061] Furthermore, when the writing lead retracts due to writing, the chuck unit 15 retracts via the writing lead, which in turn retracts the entire rotation drive mechanism 30 via the rotor 40. As a result, the rear end face of the rotation drive mechanism 30, specifically the rear end face of the cylinder member 43, presses the transmission member 50, which in turn presses the pressure sensor 24, allowing the pressure sensor 24 to detect the writing pressure.

[0062] More specifically, writing pressure via the writing lead is transmitted to the fastener 18 via the chuck body member 17, and then sequentially transmitted to the relay member 14, rotor 40, upper cam forming member 41, and cylinder member 43. The writing pressure transmitted to the cylinder member 43 is further transmitted to the transmission member 50 and then detected by the pressure sensor 24. At this time, because the rear end face of the lead case 16 and the inner surface of the receptacle 9b of the knock member 9 are separated, the retraction of the lead case 16 via the chuck body member 17 and chuck holding member 17a is not transmitted to the knock member 9. In short, according to the mechanical pencil 3, writing pressure via the writing lead is transmitted sequentially via the fastener 18 to the pressure sensor 24.

[0063] The rotation drive mechanism 30 is biased rearward by the axial spring 31, and the pressure sensor 24 is constantly subjected to a pressure equivalent to that biasing force via the transmission member 50. Therefore, the detection value of the pressure sensor 24 needs to be corrected to take into account the influence of the axial spring 31, etc.

[0064] Specifically, since the detected value output from the pressure sensor 24 is information indicating the resistance value of a resistive element deformed by pressure, the correction unit 75 converts the output from the pressure sensor 24 into a numerical pressure value. The correction unit 75 uses a pre-calculated correction table stored in the storage unit 64 to convert the pressure into a numerical pressure value. The correction table is a table for correcting the output from the pressure sensor 24 and stores resistance and pressure in correlation with each other. Generally, the resistance output from the pressure sensor 24 has a nonlinear relationship with the pressure applied to the detection surface, and therefore requires correction. However, since the relationship between resistance and pressure is unique to each sensor, pre-storing the relationship between resistance and pressure makes it possible to correct the output from the pressure sensor 24 and easily calculate the pressure applied to the detection surface. The calculated pressure is transmitted to the communication terminal 2 by the communication unit 65, where further processing is performed using the received pressure.

[0065] 5, the mechanical pencil 3 has a simpler structure and is equipped with electronic components. Furthermore, because the mechanical pencil 3 is a single-core mechanical pencil mechanism, the load on the writing lead is reduced compared to a multi-core mechanical pencil mechanism.

[0066] In the mechanical pencil 3, the transmission member 50 cooperates with the mechanical pencil mechanism 10 as a writing mechanism, and the writing lead as a writing lead transmits writing pressure to the pressure sensor 24. The writing lead is arranged along the central axis of the mechanical pencil 3, which is a knock-type writing implement, and the pressure sensor 24 is arranged eccentrically with respect to the central axis. By arranging the pressure sensor 24 eccentrically with respect to the central axis, the mechanical pencil mechanism 10 can be designed more flexibly. Furthermore, the forward and backward movement of each component accompanying the knock operation does not interfere with the pressure sensor 24, while the writing pressure is reliably transmitted, allowing for more accurate measurement of writing pressure.

[0067] In the mechanical pencil 3, the mechanical pencil mechanism 10 is arranged in the front shaft 5 and the electronic component 20 is arranged in the rear shaft 6, so that by separating the front shaft 5 and the rear shaft 6, the mechanical pencil mechanism 10 or the electronic component 20 can be easily maintained.

[0068] The shape or arrangement of the cylinder member 43 and / or the pressure sensor 24 may be changed so that the transmission member 50 is omitted and the cylinder member 43 of the rotation drive mechanism 30 presses the pressure sensor 24. For example, the cylinder member 43 and the transmission member 50 may be integrally formed. The arrangement of the pressure sensor 24 on the electronic board 21 may be changed according to the shape or arrangement of the cylinder member 43 and / or the transmission member 50. Furthermore, the rotation drive mechanism 30 may be omitted in the mechanical pencil 3. Furthermore, the pressure sensor 24 may be omitted in the mechanical pencil 3. The mechanical pencil 3 may be configured to detect the number of rotations or rotation speed of the rotor 40 using an inertia sensor, an angle sensor, or the like.

[0069] The knock member 9 has a frame-shaped connecting portion 9c, but may be configured in any way as long as it can avoid interference with the electronic component 20 and transmit the knock operation to the lead case 16. For example, the connecting portion 9c has a rectangular frame shape, but it may also be an oval frame shape or a U-shape.

[0070] Hereinafter, another embodiment of a knock-type writing instrument that provides the same effects as those described above will be described.

[0071] Figure 14 is a side view of a mechanical pencil 103, which is a knock-type writing instrument according to a second embodiment of the present invention, Figure 15 is another side view of the mechanical pencil 103 of Figure 14, Figure 16 is a cross-sectional view of the mechanical pencil 103 taken along line C-C in Figure 14, Figure 17 is a cross-sectional view of the mechanical pencil taken along line D-D in Figure 15, Figure 18 is an exploded oblique view of the mechanical pencil 103 of Figure 14, and Figure 19 is an oblique view of the mechanical pencil 103 of Figure 14 with the barrel 104 removed.

[0072] The mechanical pencil 103, like the mechanical pencil 3 described above, constitutes the communication system 1 together with the communication terminal 2. Therefore, the mechanical pencil 103 has the same functions as those described with reference to the functional block diagram shown in Fig. 7. The mechanical pencil 3 is a so-called rear-end knock type writing implement in which the operating unit 9a is located at the rear end of the barrel 4, while the mechanical pencil 103 is a so-called side-knock type writing implement in which the operating unit 109a is located on the side of the barrel 4. The mechanical pencil 103 has the same mechanical pencil mechanism 110 and electronic components 20 as the mechanical pencil 3 described above, and a description of the similar parts will be omitted.

[0073] The mechanical pencil 103 has a barrel 104 that is cylindrical overall and includes a front shaft 105 and a rear shaft 106, a tapered tip member 107 that fits onto the front end of the front shaft 105, a tail plug 108 that fits onto the rear end of the rear shaft 106, and a knock member 109 that has an operating portion 109a that protrudes from the side of the barrel 104. The barrel 104 may include the tip member 107.

[0074] 18 , the inner surface of the front end of front barrel 105 is provided with female threads 105a that can be threadedly engaged with male threads 107a provided at the rear end of tip member 107. The inner surface of the rear end of front barrel 105 is provided with a female thread (not shown) that can be threadedly engaged with male threads 106a provided at the front end of rear barrel 106. The outer surface of front barrel 105 is provided with a plurality of annular grooves 105b at equal intervals along the axial direction, which prevents fingers from slipping when writing.

[0075] The front end of the rear axle 106 is provided with a smaller-diameter reduced-diameter section 106b that is provided with a male thread section 106a. A pair of opposing through-holes, namely, fitting holes 106c, are provided on the side surface near the rear end of the rear axle 106. Furthermore, a slide hole 106d, which is a long, narrow rectangular through-hole that extends in the axial direction, is provided in the axially central section of the rear axle 106, i.e., in a section of the axle tube 104 that is closer to the rear than the central section.

[0076] The tail plug 108 has a cylindrical front half body 108a that is inserted into the rear end of the rear barrel 106, and a flat rear half body 108b that surrounds the connection portion 23a of the charging portion 23 and has an opening similar to the opening of the connection portion 23a. Therefore, the charging portion 23 is supported so as not to rotate around the central axis by being inserted into the rear half body 108b. A pair of opposing mating pieces 108c, defined by parallel slits, are provided on the side of the front half body 108a. A locking protrusion 108d is provided on the surface of each mating piece 108c.

[0077] When the tail plug 108 is inserted into the rear end of the rear axle 106, the locking projection 108d is pressed by the edge of the opening at the rear end of the rear axle 106, causing the fitting piece 108c to elastically deform radially inward. Next, when the locking projection 108d reaches the fitting hole 106c of the rear axle 106, the fitting piece 108c returns to its original shape, and the locking projection 108d is positioned within the fitting hole 106c, completing the fitting of the tail plug 108 to the rear axle 106.

[0078] Figure 20 is a perspective view of the knock member 109. The knock member 109 has a mountain-shaped operating portion 109a that faces diagonally rearward and has a concavely curved slope to make it easier for the user to perform a knock operation when the knock member 109 is placed on the side of the barrel 104. The knock member 109 is provided with a sliding surface 109b that faces the side of the barrel 104 and a pair of rail protrusions 109c that protrude from the sliding surface 109b and extend parallel along the longitudinal direction. The sliding surface 109b is formed complementarily with a portion of the outer surface of the opposing barrel 104, i.e., the outer surface of the rear axle 106. A locking protrusion 109d extending in the longitudinal direction is provided on the outer surface of each of the pair of rail protrusions 109c.

[0079] FIG. 21 is a perspective view of the transmission member 150, and FIG. 22 is a longitudinal cross-sectional view of the transmission member 150. The transmission member 150 is a cylindrical member. The transmission member 150 has a main body 151 and two flanges 152 provided at the rear end of the main body 151 and a portion spaced forward from the rear end. The transmission member 150 has a rectangular cutout 153 cut out of one flange 152 and the main body 151 along the axial direction from the rear end face including one flange 152 to just before the other flange 152. Chamfered portions 154 are provided on both edges of the flange 152 near the cutout 153. A partition wall 156 is provided on the inner surface of the main body 151 near the front end. A circular through-hole 157 is provided centered on the central axis of the transmission member 150. The through-hole 157 has an inner diameter slightly larger than the outer diameter of the lead case 16 so that the lead case 16 can pass through.

[0080] 23 is a perspective view of the connecting member 160. The connecting member 160 has a columnar portion 161 with a sector-shaped cross section and a cylindrical receiving portion 162 provided at the front end of the columnar portion 161. The receiving portion 162 is configured to receive the rear end of the lead case 16 that has passed through the rotation drive mechanism 30. One circumferential side of the columnar portion 161 is provided with a curved surface 163 that is formed complementarily to a portion of the outer surface of the columnar power source 22 along the longitudinal direction. Note that the columnar portion 161 may have any cross section and shape other than a sector shape.

[0081] FIG. 24 is a perspective view of the fixing member 170. The fixing member 170 has an outer surface complementary to the inner surface of the rear body 106 and is formed in a semi-cylindrical shape, like a cylinder cut in half lengthwise. The fixing member 170 has a retaining portion 171 that extends circumferentially and axially from the edge of the semi-cylindrical shape extending in the axial direction, and has a continuous cylindrical outer surface. A groove 172 extending in the axial direction is provided at the base of the retaining portion 171. A plurality of support ribs 173 extending in a direction perpendicular to the axial direction are provided on the inner surface of the fixing member 170. A support protrusion 174 extending parallel to the axial support rib 173 is provided at the front end of the retaining portion 171.

[0082] 16 to 19 , the fixing member 170 is fixed within the barrel 104. The electronic board 21 of the electronic component 20 is attached to the fixing member 170. Specifically, the longitudinal edges of the electronic board 21 are received in the grooves 172, and the electronic board 21 is supported by the support ribs 173 and the support protrusions 174. As a result, the electronic board 21 is fixed by the charging section 23 being disposed within the rear half 108b of the tail plug 108, and is further fixed by the fixing member 170. Therefore, the pressure sensor 24 disposed on the electronic board 21 is also fixed relative to the barrel 104. The pressure sensor 24 is disposed eccentrically with respect to the central axis of the mechanical pencil 103.

[0083] Figure 25 is an enlarged cross-sectional view of the center portion of mechanical pencil 103 in Figure 14. Transmission member 150 has main body 151 inserted into reduced-diameter portion 106b of rear barrel 106. That is, the outer diameter of main body 151 is formed slightly smaller than the inner diameter of reduced-diameter portion 106b of rear barrel 106, while the outer diameter of flange 152 is formed larger than the inner diameter of reduced-diameter portion 106b of rear barrel 106. As a result, transmission member 150 is disposed so as to be movable back and forth relative to the rear end of rear barrel 106. The front end surface of transmission member 150 abuts against rotation drive mechanism 30, specifically the rear end surface of cylinder member 43, inside front barrel 5.

[0084] The contact surface 155 of the transmission member 150 is disposed so as to contact the pressure sensor 24 disposed on the electronic board 21. That is, within the barrel 4, the rotation drive mechanism 30 is urged rearward by the barrel spring 31, which in turn urges the transmission member 50 rearward, causing the contact surface 55 of the transmission member 50 to contact the opposing pressure sensor 24.

[0085] The knock member 109 is attached to the axle tube 104 by inserting the rail protrusions 109c into the slide hole 106d of the rear axle 106. When the rail protrusions 109c are inserted into the slide hole 106d, the locking protrusions 109d are pressed by the opening edge of the slide hole 106d, causing the rail protrusions 109c to elastically deform so that they approach each other. Next, when the locking protrusions 109d leave the slide hole 106d, the rail protrusions 109c return to their original position and are positioned within the rear axle 106, completing the attachment of the knock member 109 to the axle tube 104. The knock member 109 can be advanced or retreated relative to the axle tube 104 along the slide hole 106d, with the locking protrusions 109d locking onto the inner surface of the rear axle 106 near the slide hole 106d. Since the sliding surface 109b of the knock member 109 is formed complementarily to the outer surface of the barrel 104, the knock member 109 can slide more smoothly along the barrel 104 when the knock member 109 moves.

[0086] The connecting member 160 is disposed within the barrel 104 so as to connect the knock member 109 and the transmission member 150. That is, the connecting member 160 is disposed within the barrel 104 so that the receiving portion 162 is housed within the transmission member 150 via the notch 153 of the transmission member 150. At this time, the chamfered portion 154 is provided at the entrance portion of the notch 153 of the transmission member 150, so that the receiving portion 162 of the connecting member 160 is smoothly guided into the transmission member 150. The outer diameter of the receiving portion 162 is formed smaller than the inner diameter of the transmission member 150. Therefore, the connecting member 160 is disposed so as to be movable back and forth relative to the transmission member 150 while the receiving portion 162 is housed within the transmission member 150.

[0087] The coil spring 32 is disposed within the transmitting member 150. The front end of the coil spring 32 is supported by the partition wall 156 of the transmitting member 150, and the rear end of the coil spring 32 abuts against the annular front end surface of the receiving portion 162 of the connecting member 160. As a result, the coil spring 32 biases the connecting member 160 rearward. The rear end of the columnar portion 161 of the connecting member 160 is disposed so as to face the front ends of the pair of rails of the knock member 109. Therefore, the coil spring 32 biases the knock member 109 rearward via the connecting member 160.

[0088] By performing a knocking operation that presses the knock member 109, specifically the operating portion 109a, forward against the biasing force of the coil spring 32, the lead case 16 moves forward via the connecting member 160. This allows the writing lead to be advanced, as described above in the mechanical pencil 3. Meanwhile, during a writing operation, as described above in the mechanical pencil 3, the rotation drive mechanism 30 moves backward via the writing lead, and the rear end face of the cylinder member 43 presses the transmission member 150, which in turn presses the pressure sensor 24. As a result, the writing pressure can be detected by the pressure sensor 24.

[0089] In the mechanical pencil 103, the knock operation on the knock member 109 arranged on the side of the barrel 104 is transmitted to the lead case 16 via the connecting member 160, but the knock member 109 and the connecting member 160 can be configured as desired as long as they can transmit the knock operation to the lead case 16.

[0090] Fig. 26 is a vertical cross-sectional view of a ballpoint pen 203 which is a knock-type writing instrument according to a third embodiment of the present invention, Fig. 27 is another vertical cross-sectional view of the ballpoint pen 203 of Fig. 26, and Fig. 28 is an exploded perspective view of the ballpoint pen 203 of Fig. 26. Fig. 29 is an enlarged cross-sectional view of the central portion of the ballpoint pen 203 of Fig. 26. Fig. 30 is a perspective view of an inner cylinder 230.

[0091] Like the mechanical pencil 3 described above, the ballpoint pen 203 constitutes the communication system 1 together with the communication terminal 2. Therefore, the ballpoint pen 203 has the same functions as those described with reference to the functional block diagram shown in FIG. 7 . The outer shape of the ballpoint pen 203 is substantially the same as that of the mechanical pencil 103. Instead of the mechanical pencil mechanism 110 described above in the mechanical pencil 103, the ballpoint pen 203 has a ballpoint pen mechanism 210 and an electronic component 20 as a writing mechanism, and a description of the similar parts will be omitted. The ballpoint pen mechanism 210 is a well-known mechanism having a refill 211 as a writing mechanism, a cylindrical inner cylinder 230 equipped with an outer cam 240, a pressing member 250, and a cylindrical rotor 260. Therefore, the configuration of the ballpoint pen mechanism 210 will be briefly described below.

[0092] The inner cylinder 230 is disposed within the front axle 105, forward of the rear axle 106. The outer diameter of the inner cylinder 230 is slightly smaller than the inner diameter of the front axle 105. Therefore, the inner cylinder 230 is disposed within the front axle 105 so as to be movable back and forth. The inner cylinder 230 is biased rearward by the axle spring 31. The rearward movement of the inner cylinder 230 is restricted by the rear end surface of the inner cylinder 230 abutting against the front end surface of the transmission member 150. A plurality of outer cams 240, which are cam protrusions, are formed on the inner surface of the inner cylinder 230. Guide grooves 241 are provided between adjacent outer cams 240. A pressing member 250 is disposed within the inner cylinder 230, and a rotor 260 is disposed in front of the pressing member 250. The pressing member 250 is disposed non-rotatably relative to the inner cylinder 230, while the rotor 260 is disposed rotatably relative to the inner cylinder 230.

[0093] The pressing member 250 has a cam surface 251 provided on its front end surface and a plurality of locking protrusions 252 provided on the outer surface of its front end. The rotor 260 has a cam receiving surface 261 complementary to the cam surface 251 of the pressing member 250 and a plurality of inner cams 262, which are cam protrusions provided on the outer surface of its front end. The refill 211 is integrally attached to the rotor 260. The rotor 260 is urged rearward together with the refill 211 by a coil spring 212. The front end of the coil spring 212 is supported by the inner surface of the front shaft 105, and the rear end of the coil spring 212 abuts against the inner surface of the rotor 260. Therefore, the coil spring 212 urges the rotor 260 rearward.

[0094] When a knocking operation is performed to press the knock member 109 forward against the force of the coil spring 32, the refill 211 switches between a writing state (Figures 27 and 28) in which the writing part at the tip of the refill 211 protrudes from the barrel 104, and a non-writing state (not shown) in which the writing part is retracted into the barrel 104.

[0095] For example, when the ballpoint pen 203 is in a non-writing state, the locking protrusion 252 of the pressing member 250 and the inner cam 262 of the rotor 260 are disposed in the guide groove 241 of the outer cam 240. When the knock member 109 is moved forward by a knock operation, the pressing member 250 advances via the connecting member 160. As the pressing member 250 advances, the inner cam 262 of the rotor 260 passes the outer cam 240 and disengages from the guide groove 241. At this time, the cam surface 251 of the pressing member 250 and the cam receiving surface 261 of the rotor 260 cooperate to rotate the rotor 260 about the central axis. Next, when the pressure on the knock member 109 is released, the rotor 260 retreats, the inner cam 262 and the outer cam 240 engage with each other in the axial direction, and the ballpoint pen 203 enters a writing state. The knock member 109 moves back together with the connecting member 160 due to the biasing force of the coil spring 32 and returns to its original position.

[0096] When the knocking operation is performed again while the ballpoint pen 203 is in the writing state, the forward movement of the pressing member 250 releases the axial engagement between the inner cam 262 of the rotor 260 and the outer cam 240. Next, the cam surface 251 of the pressing member 250 and the cam receiving surface 261 of the rotor 260 cooperate to rotate the rotor 260 about the central axis. When the pressure on the knock member 109 is released, the rotor 260 retreats and the inner cam 262 is again positioned within the guide groove 241 of the outer cam 240, and the ballpoint pen 203 enters the non-writing state.

[0097] When refill 211 is moved backward by writing, rotor 260 is moved backward together with refill 211. When rotor 260 is moved backward, inner cam 262 of rotor 260 and outer cam 240 of inner cylinder 230 are engaged in the axial direction, so inner cylinder 230 is also moved backward. As a result, the rear end surface of inner cylinder 230 presses transmission member 150, which presses pressure sensor 24, allowing pressure sensor 24 to detect the writing pressure.

[0098] As a result, it is possible to provide a ballpoint pen equipped with electronic components with a simpler structure, not only for mechanical pencils but also for ballpoint pens. Furthermore, since the refill 211 is arranged along the central axis of the ballpoint pen 203 and the pressure sensor 24 is arranged eccentrically relative to the central axis, it is possible to design the ballpoint pen mechanism 210 more flexibly.

[0099] In the mechanical pencil 3 according to the first embodiment and the mechanical pencil 103 according to the second embodiment, part or all of the operating portion 9a of the knock member 9, the operating portion 109a of the knock member 109, and the tail cap 108 may be configured as an erasing portion capable of erasing handwriting made with a writing lead. If the writing lead is a normal writing lead containing graphite, the erasing portion is made of eraser components. The writing lead used in the mechanical pencil 3 and the mechanical pencil 103 may be a thermochromic writing lead. In this case, the mechanical pencil 3 and the mechanical pencil 103 are thermochromic writing implements, and the handwriting made with the mechanical pencil 3 and the mechanical pencil 103 can be thermochromic due to the frictional heat generated when rubbed by the friction body that is the erasing portion.

[0100] Here, a thermochromic writing lead refers to an ink that maintains a predetermined color (first color) at room temperature (e.g., 25°C), changes to a different color (second color) when heated to a predetermined temperature (e.g., 60°C), and then returns to the original color (first color) when cooled to a predetermined temperature (e.g., -5°C). In the mechanical pencil 3 and mechanical pencil 103 using a thermochromic writing lead, the second color is colorless, and "erasing" refers to heating a line drawn with the first color (e.g., red) to make it colorless. Therefore, the frictional portion serving as the erasing portion rubs against the writing surface on which the line was drawn, generating frictional heat, thereby changing the drawn line to colorless, i.e., erasing it. Naturally, the second color may be a color other than colorless.

[0101] In the ballpoint pen 203 according to the third embodiment, the operating portion 109a of the knock member 109 and part or all of the tail plug 108 may be configured as an erasing portion capable of erasing handwriting made with the refill 211. The refill 211 may contain thermochromic ink. In this case, the ballpoint pen 203 is a thermochromic writing implement, and the handwriting made with the ballpoint pen 203 can be thermochromic due to frictional heat generated when rubbed with the friction body serving as the erasing portion.

[0102] Here, thermochromic ink refers to ink that maintains a predetermined color (first color) at room temperature (e.g., 25°C), changes to a different color (second color) when heated to a predetermined temperature (e.g., 60°C), and then returns to the original color (first color) when cooled to a predetermined temperature (e.g., -5°C). In a ballpoint pen 203 using thermochromic ink, the second color is colorless, and "erasing" refers to heating a line drawn in the first color (e.g., red) to make it colorless. Therefore, a frictional body serving as an erasing part rubs against a writing surface on which the line was drawn, generating frictional heat, thereby changing the drawn line to colorless, i.e., erasing it. Naturally, the second color may be a color other than colorless.

[0103] In the third embodiment described as the ballpoint pen 203, the ballpoint pen refill 211 may be replaced with a knock-type writing implement having other types of writing material such as a touch pen or an eraser.

[0104] DESCRIPTION OF SYMBOLS 3 Mechanical pencil 4 Barrel 5 Front barrel 6 Rear barrel 7 Tip member 8 Tail plug 9 Knock member 9a Operation unit 10 Mechanical pencil mechanism 11 Tip pipe 12 Holding chuck 13 Slider 14 Relay member 15 Chuck unit 16 Lead case 20 Electronic component 21 Electronic board 22 Power supply 24 Pressure sensor 30 Rotation drive mechanism 31 Shaft spring 32 Coil spring 40 Rotor 50 Transmission member

Claims

1. A knock-type writing instrument comprising: a barrel; a knock member with an operating unit; a writing body mechanism having a writing body and configured to enter a writing state by knocking the operating unit; an electronic component including a writing pressure sensor that detects the writing pressure applied to the writing body; and a transmission member that cooperates with the writing body mechanism and is configured to transmit the writing pressure applied to the writing body to the writing pressure sensor, wherein the writing body is arranged along the central axis of the knock-type writing instrument and the writing pressure sensor is arranged eccentrically with respect to the central axis.

2. A knock-type writing instrument as described in claim 1, wherein the writing mechanism comprises a chuck unit having a writing lead, a chuck body member that grips the writing lead, and a fastener that can surround the front end of the chuck body member, and is capable of gripping and releasing the grip of the writing lead by moving the chuck body member back and forth, and is configured so that the chuck body member retracts relative to the fastener when the writing lead retracts.

3. A knock-type writing instrument as described in claim 2, wherein the writing mechanism has a rotational drive mechanism equipped with a rotor, and the rotational drive mechanism is configured to rotate the rotor in one direction in response to axial backward movement due to writing pressure applied to the writing lead held by the chuck unit and axial forward movement due to the release of writing pressure.

4. A knock-type writing implement according to claim 3, wherein the rotary drive mechanism is retracted by the writing pressure applied to the writing lead, and the writing pressure sensor detects the writing pressure as the rotary drive mechanism retracts.

5. A knock-type writing implement according to any one of claims 2 to 4, wherein a part or all of the operating portion is an erasing portion capable of erasing handwriting made with the writing lead.

Images