Pen tip for input pen and input pen

Abstract

To provide a pen tip for an input pen and the input pen configured to prevent an input screen from being contaminated while providing a comfortable writing feel.SOLUTION: A pen tip 20 of an input pen is brought into physical contact with an input screen of an input device for input operation, the pen tip including a contact surface 22a which is brought into contact with the input screen, a tip section 22 including the contact surface, and a connection section 21. The tip section is formed by containing a filler and a binder. The wear amount of the tip section is 1 to 100 μm. The filler is selected from a group consisting of boron nitride, mica, talc, calcium carbonate, and graphite.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pen tip for an input pen and an input pen.

Background Art

[0002] In recent years, touch pads, touch panels, etc. (hereinafter also collectively referred to as "input devices") that perform input by physical contact on an operation screen (input screen) have been widely used. When performing an input operation on such an input device, an input pen corresponding to the input method of the input device (for example, a capacitance method, an electromagnetic induction method, etc.) is used.

[0003] Patent Document 1 discloses an input pen that suppresses damage to the operation surface of an input device and the pen tip and has excellent conductivity. The input pen includes a ball that contacts the input device and an elastic member that constantly presses the ball in the front end direction, and the ball and the elastic member are formed of a conductive material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Regarding the pen tip of the input pen, excellent strength (especially bending strength) is required so as to be able to cope with various writing pressures. Furthermore, in recent years, the usage environment and usage situation of the input pen have become diverse, and a writing feel like that of a writing instrument has been required.

[0006] However, in the conventional pen tip, although approaches to improving strength and wear resistance have been actively made, the improvement of writing feel has been insufficiently studied. Further, although improving the wear resistance of the pen tip can achieve an improvement in writing feel, there is a risk that the handwriting will remain on the input screen and the input screen will become dirty, and at present, it has not reached a level that can meet various needs.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide a pen tip for an input pen and an input pen that are excellent in writing feel and can suppress the adhesion of dirt to the input screen.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention includes the following aspects.

[0009] [1] A pen tip of an input pen that performs input by physical contact on an input screen of an input device, comprising a contact surface that contacts the input screen and a tip portion that includes the contact surface, the tip portion including a matrix material and a binder, and the wear amount of the tip portion being 1 μm or more and 100 μm or less, a pen tip for an input pen. [2] The pen tip for an input pen according to [1] above, wherein the matrix material is selected from the group consisting of boron nitride, mica, talc, calcium carbonate, and graphite. [3] The pen tip for an input pen according to [1] or [2] above, wherein the arithmetic mean height Sa of the tip portion is 0.4 μm or less. [4] The pen tip for an input pen according to any one of [1] to [3] above, wherein the tip portion has porosity and the porosity of the tip portion is 0 to 15%. [5] The pen tip for an input pen according to any one of [1] to [4] above, wherein the bending strength of the tip portion is 200 MPa or more. [6] The pen tip for an input pen according to any one of [1] to [5] above, wherein the radius of curvature R of the contact surface of the tip portion is 0.1 to 1.5 mm. [7] The pen tip for an input pen according to any one of [1] to [6] above, wherein the input device is of an electromagnetic induction type. [8] An input pen that performs input by physical contact on the input screen of an input device, comprising a shaft cylinder that extends axially along a central axis, and a pen tip for an input pen according to any one of [1] to [7] above.

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a pen tip for an input pen and an input pen that are excellent in writing feel and can suppress the adhesion of dirt to the input screen.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0012] The pen tip for an input pen and the input pen according to an embodiment of the present invention will be described with reference to FIGS. 1 to 2. In the following description, the pen tip for input may be simply abbreviated as "pen tip".

[0013] <Input Pen> FIG. 1 is a side view showing the input pen 1 of the present embodiment. The input pen 1 according to the present embodiment is an input pen that performs input by physical contact on the input screen of an input device. As shown in FIG. 1, it includes a shaft cylinder 10 that extends axially along a central axis O, and a pen tip 20. The shaft cylinder 10 and the pen tip 20 are coaxially arranged with each other with the central axis O as a common axis.

[0014] The definition of the directions used in the present embodiment will be described. In this embodiment, the direction in which the central axis O of the input pen 1 extends, that is, the direction along the central axis O, is referred to as the axial direction. In the axial direction, the shaft cylinder 10 that constitutes the body of the input pen 1 and the pen tip 20 are arranged at different positions from each other. Among the axial directions, the direction from the shaft cylinder 10 toward the pen tip 20 is referred to as the front side, and the direction from the pen tip 20 toward the shaft cylinder 10 is referred to as the rear side. For this reason, the axial direction may be referred to as the front-rear direction. In each figure, the axial direction (front-rear direction) corresponds to the Y-axis direction. The front side corresponds to the -Y side, and the rear side corresponds to the +Y side. Also, the direction orthogonal to the central axis O may be referred to as the radial direction.

[0015] Each component of the input pen 1 will be described. As shown in FIG. 1, the shaft cylinder 10 is cylindrical with the central axis O as the center and extends in the axial direction. The material of the shaft cylinder 10 is not particularly limited, but is, for example, a resin having polycarbonate or the like as the main component.

[0016] The shaft cylinder 10 may be composed of a single member, or may be composed by combining a plurality of members. When the shaft cylinder 10 is composed of a plurality of members, for example, a plurality of cylindrical members may be combined by screwing, fitting, and bonding. Also, when the shaft cylinder 10 is composed of a plurality of members, in order to improve the writing feel, the material, shape, dimensions, etc. of the vicinity of the front end of the shaft cylinder 10 (that is, the portion corresponding to the holding part during use) may be appropriately adjusted.

[0017] Although not particularly shown, each component member of the shaft cylinder 10 may be manufactured by so-called injection molding or the like in which a molten resin material is injected and solidified between a pair of molds and cores.

[0018] The shaft cylinder 10 has a portion composed of an opaque member such as black, for example. Also, the shaft cylinder 10 may have a portion composed of a colorless transparent member, for example. Note that the transparent member may be a transparent member to which a predetermined color is imparted. In this embodiment, "transparent" is a concept that includes "semi-transparent". The opaque member may be an opaque member to which a predetermined color other than black is imparted.

[0019] At the front end portion 10a (on the -Y direction side) of the shaft cylinder 10, a fixing portion (not shown) for fixing the pen tip 20 described later is provided. The end portion 10a of the shaft cylinder 10 and the pen tip 20 are detachably fixed at the fixing portion by screwing, fitting, or the like.

[0020] <Pen tip> Next, the pen tip 20 according to the present embodiment will be described. FIG. 2 and FIG. 3 are side views showing the pen tip 20 of the present embodiment. The pen tip 20 according to the present embodiment is the pen tip 20 that constitutes the input pen 1 (see FIG. 1).

[0021] As shown in FIG. 2, the pen tip 20 includes a connecting portion 21 that connects to the shaft cylinder 10 of the input pen 1, and a tip portion 22 that is provided on the input device side (-Y direction side) with respect to the connecting portion 21 and has a contact surface 22a with the input screen. As will be described in detail later, the tip portion 22 and the connecting portion 21 may be integrally formed.

[0022] The connecting portion 21 is detachably fixed to the front end portion 10a of the shaft cylinder 10 by screwing, fitting, or the like. The connecting portion 21 and the shaft cylinder 10 are coaxially arranged with the central axis O as a common axis (see FIG. 1).

[0023] The connecting portion 21 has a cylindrical shape centered on the central axis O and extends in the axial direction. The material of the connecting portion 21 is not particularly limited, and it may be made of the same material as the tip portion 22 described later. When the tip portion 22 and the connecting portion 21 are each formed of a separate member, examples of the material of the connecting portion 21 include resins mainly composed of polycarbonate or the like.

[0024] The tip portion 22 is provided on the input device side (-Y direction side) with respect to the connecting portion 21 and has a contact surface 22a with the input screen. The tip portion 22 is, for example, a portion exposed from the front end portion 10a of the shaft cylinder 10. Note that the tip portion 22 may be accommodated within the shaft cylinder 10. That is, for example, during use, the tip portion 22 may be in a form exposed from the end portion 10a.

[0025] The shape of the tip portion 22 is not particularly limited. For example, the shape of the tip portion 22 may be a shape in which the diameter decreases as it goes toward the front side (-Y direction side). Also, for example, the tip portion 22 may be configured with substantially the same diameter as the connecting portion 21. From the viewpoint of improving the writing feeling, the shape of the tip portion 22 is preferably a shape in which the diameter decreases as it goes toward the front side (-Y direction side). The shape of the tip portion 22 may also be a substantially conical shape as shown in FIG. 2.

[0026] The pen tip 20 may be composed of a single member or may be configured by combining a plurality of members. That is, the tip portion 22 and the connecting portion 21 may be integrally formed. Also, when the tip portion 22 and the connecting portion 21 are integrally formed, the materials of the tip portion 22 and the connecting portion 21 may be the same.

[0027] When the shape of the tip portion 22 is a substantially conical shape, the tip shape of the front side (-Y direction side) of the tip portion 22 is preferably a protruding curved surface shape having an R surface. That is, the contact surface 22a is preferably curved in a side view. Note that the "R surface" referred to here may be a multi-curved surface.

[0028] The dimensions of the tip portion 22 are not particularly limited either. The diameter φ of the tip portion may be 0.1 mm to 10 mm.

[0029] The radius of curvature R of the contact surface 22a of the tip portion 22 is preferably 0.1 to 1.5 mm. When the radius of curvature R is less than 0.1 mm, pressure tends to concentrate on the pen tip, particularly at the tip of the tip portion 22, and thus it may be easily worn. Therefore, the radius of curvature R is preferably 0.1 mm or more. The radius of curvature R is more preferably 0.2 mm or more, and even more preferably 0.3 mm or more. On the other hand, when the radius of curvature R exceeds 1.5 mm, it is likely to get caught during writing. Therefore, the radius of curvature R is preferably 1.5 mm or less. The radius of curvature R is more preferably 1.2 mm or less, and even more preferably 1.0 mm or less.

[0030] The axial length L of the pen tip 20 is not particularly limited and may be appropriately adjusted according to the length of the input pen 1 or the shaft cylinder 10. For example, the axial length L of the pen tip 20 is 5 mm to 60 mm.

[0031] The tip portion 22 includes a core body including a bulk material and a binder. Note that the entire tip portion 22 does not necessarily have to be composed of the core body, and at least a part of the tip portion 22, particularly the contact surface 22a where writing feel and strength are required and the vicinity thereof, may be composed of the core body. Naturally, the entire tip portion 22 may be composed of the core body. Hereinafter, the core body constituting the tip portion 22 will be described in detail.

[0032] The core body constituting the tip portion 22 includes a bulk material and a binder as components. In addition to a good writing feel, it is desirable that the pen tip 20 of the present embodiment also has appropriate strength. Further, when a colorant is contained in the tip portion 22, it is preferably one that does not inhibit its coloring.

[0033] Further, in the present embodiment, in order to realize a good writing feel of the pen tip, a core body is adopted in which the pen tip is moderately worn during use, like a pencil lead. Specifically, the wear amount of the tip portion 22 is 1 μm or more. If the wear amount is too small, it becomes difficult to achieve a good writing feel of the pen tip. Therefore, the wear amount of the tip portion 22 is set to 1 μm or more. Preferably it is 5 μm or more, more preferably 10 μm or more. On the other hand, when the wear amount of the tip portion 22 is excessively large, the handwriting remains on the input screen and the screen gets dirty. Therefore, the wear amount is set to 100 μm or less. Preferably it is 50 μm or less, more preferably 40 μm or less.

[0034] Note that the "wear amount" referred to in this embodiment is the wear amount when written in accordance with the concentration evaluation method of JIS S 6005:2019. More specifically, when writing with the A method (record type), the writing angle is 75°, the load is 400 gf, and the writing distance is 6 m. The "wear amount" is defined as the change in the length (core length) of the core when writing on a plastic plate (manufactured by ELECOM Co., Ltd., paper-like antireflection film "TB-WIPSFLAPLL"). Also, the core length can be obtained by measuring the difference in the length of the tip portion 22 before and after the measurement test.

[0035] As described above, in this embodiment, in order to improve the writing feeling, a core of the pen tip that is moderately worn during use is applied. Specifically, as the extender, those selected from the group consisting of boron nitride, mica, talc, calcium carbonate, and graphite are preferable. Note that if an actual pencil core is used for the pen tip, handwriting will remain on the input screen and the screen will become dirty. From the viewpoint of suppressing the remaining handwriting on the input screen, it is preferable to use a white extender as the main component of the core. Also, considering the writing feeling, the extender is preferably boron nitride, mica, or talc. More preferably, the extender is boron nitride. By making the skeleton of the core constituting the tip portion 22 boron nitride, it is possible to further ensure the strength of the pen tip and promote appropriate wear of the pen tip during use, so that the writing feeling of the pen tip can be further improved.

[0036] The binder is not particularly limited as long as it can bind the extender as described above that forms the main body of the core, and may be an inorganic binder (hereinafter referred to as an inorganic binder) or an organic binder (hereinafter referred to as an organic binder). Note that considering the strength and writing feeling of the pen tip, an inorganic binder is preferable.

[0037] Examples of the inorganic binder include clays such as kaolinites, halloysites, montmorillonites, sericites, bentonites, ceramics, zeolite, diatomaceous earth, activated clay, silica, etc. Further, a precursor of the inorganic binder can be blended with the raw material of the core, and can be changed into the inorganic binder by firing treatment or the like in the manufacturing process. Examples of such a precursor include aluminum phosphate, silicone resin, silicone rubber, etc. These inorganic binders or their precursors can be used alone or in combination. Among them, silica is preferable as the inorganic binder from the viewpoints of the color tone of the appearance and the smoothness during writing.

[0038] The mixing ratio of the extender and the binder is not particularly limited, but is preferably 5:5 to 8:2 by mass ratio, and more preferably 6:4 to 7:3.

[0039] In the present embodiment, the core includes an extender and a binder. A general pencil lead is manufactured by molding a mixture of an extender and a binder by a method such as extrusion molding and then firing, but the same method can also be applied in the manufacturing method of the pen tip of the present embodiment. That is, the pen tip according to the present embodiment can be manufactured by molding a mixture of an extender and a binder and then firing.

[0040] Note that the pen tip of the present embodiment can also be manufactured by compressing a mixture of the above extender, binder, and further, if necessary, an inorganic substance, a water-soluble resin, etc. at high pressure, and then immersing it in water, a solvent, etc. to remove the inorganic substance, the water-soluble resin, etc.

[0041] The core used in the present embodiment is preferably a porous core. The porosity of the porous core is not particularly limited, but for example, it may be in the range of 0.1 to 20%. By increasing the porosity of the core, the amount of wear can be increased. On the other hand, if the porosity of the core is greater than 20%, the strength of the obtained core may decrease. Also, if the porosity is too high, the amount of wear may become excessively large. Therefore, when using a porous core as the tip portion 22, the porosity is preferably in the range of 0.1 to 20%, more preferably in the range of 0.1 to 10%, and even more preferably in the range of 0.5 to 5%. By using a core having a porosity within this range, it is possible to more stably achieve both a good writing feel of the pen tip, high strength, and suppression of adhesion of dirt to the input screen.

[0042] The porosity of the core can be measured by the following method with reference to JIS R1634 (1998). First, measure the dry mass (W1) of the core. Next, immerse it in a liquid with good permeability (for example, benzyl alcohol), and after absorbing the liquid until the pores of the core are saturated, measure the mass in the liquid (W2). Further, take out the core from the liquid, remove the liquid adhering to its surface, and then measure the saturated liquid mass (W3). Using these measured values, the porosity is obtained by the following formula (1).

[0043] Porosity = (W3 - W1) / (W3 - W2) × 100 ··· (1)

[0044] The tip portion 22 according to the present embodiment may be filled with a colored ink in the above-described core. The colored ink contains a colorant and a plasticizer as main components.

[0045] As the colorant, a dye or a pigment can be used. Also, a colored pigment obtained by dyeing a resin with a dye can be used. Generally, since a dye easily penetrates into the core when made into a solution, the production becomes easy.

[0046] The dyes that can be used in the present embodiment are not particularly limited, and examples include general dyes and fluorescent dyes.

[0047] The pen tip 20 (particularly the tip portion 22) of the present embodiment may contain various additives as long as its performance is not affected. Specific additives include resins, oils, and the like.

[0048] The arithmetic mean height Sa of the tip portion 22 is preferably 0.40 μm or less. The smaller the surface roughness Ra, the smoother and better the writing feel can be realized. That is, by adjusting the core body constituting the tip portion 22 of the pen tip 20 as described above and reducing the arithmetic mean height Sa of the tip portion 22, a pen tip 20 that can realize a good writing feel can be provided. The arithmetic mean height Sa of the tip portion 22 is preferably 0.35 μm or less. The lower limit value of the arithmetic mean height Sa of the tip portion 22 is not particularly limited, but in practice, it is 0.00001 μm or more.

[0049] Note that the target portion whose arithmetic mean height Sa should be controlled within the above range does not have to be the entire tip portion 22. That is, if the arithmetic mean height Sa of the contact surface 22а that contacts the input screen of the input device is within the above range, the above effects can be enjoyed.

[0050] The arithmetic mean height Sa of the tip portion 22 is measured using a white light interferometer "NewView" (manufactured by Zygo Corporation). As the measurement conditions, the magnification is set to ×10, and the waviness removal is set automatically.

[0051] The tip portion 22 of the present embodiment can achieve high strength by using a core body manufactured by firing. The bending strength of the pen tip by the tip portion 22 of the present embodiment is preferably 200 MPa or more. More preferably, it is 300 MPa or more. The upper limit of the bending strength is not particularly limited, but in practice, the upper limit of the bending strength may be set to 450 MPa or less. Here, the "bending strength" can be measured by the method defined in JIS S 6005:2019.

[0052] Next, a modified example of the pen tip of the present embodiment will be described. FIG. 3 is a side view showing a modified example of the pen tip of the present embodiment.

[0053] As shown in FIG. 3, in a modified example of the present embodiment, the pen tip 120 may be configured such that the tip portion 122 and the connecting portion 121 having different diameters are separate members.

[0054] The axial length L1 of the connecting portion 121 is not particularly limited and may be appropriately adjusted according to the length of the input pen 1 or the shaft cylinder 10 and the fixing means for the end portion 10a. For example, the axial length L1 of the connecting portion 121 is 5 mm to 60 mm. Preferably it is 10 mm to 30 mm, and more preferably it is 15 mm to 25 mm.

[0055] The diameter φ1 of the connecting portion 121 is not particularly limited and may be appropriately adjusted according to the dimensions of the input pen 1 and the fixing means for the end portion 10a. For example, the diameter φ1 of the connecting portion 121 is 0.1 mm to 5 mm. Preferably it is 0.3 mm to 2 mm, and more preferably it is 0.5 mm to 1.5 mm.

[0056] The tip portion 122 is provided on the input device side (-Y direction side) rather than the connecting portion 121 and has a contact surface 22a with the input screen.

[0057] The shape of the tip portion 122 is not particularly limited. For example, the shape of the tip portion 122 may be a shape in which the diameter decreases as it goes toward the front side (-Y direction side). Also, for example, the tip portion 122 may be configured to have substantially the same diameter from the connecting portion 121 and the rear end 122b on the side (+Y direction side) to the contact surface 22a. From the viewpoint of improving the writing feeling, the shape of the tip portion 122 is preferably a shape in which the diameter decreases as it goes toward the front side (-Y direction side). The shape of the tip portion 122 may be, for example, a shape in which a cylindrical portion and a conical portion are combined as shown in FIG. 3. That is, the shape of the tip portion 122 may be a substantially cylindrical shape on the connecting portion 121 side and a conical shape in which the diameter decreases as it goes toward the front side (-Y direction side).

[0058] The dimensions of the tip portion 122 are not particularly limited. However, in order to stably fix the tip portion 122 to the end portion 10a of the shaft cylinder 10, the diameter φ2 of the rear end 122b on the connecting portion 121 side (+Y direction side) of the tip portion 122 is preferably equal to or larger than the diameter φ1 of the connecting portion 121. For example, the diameter φ2 of the tip portion 122 is 0.1 mm to 10 mm.

[0059] Also, the axial length L2 of the tip portion 122 is not particularly limited and may be appropriately adjusted according to the length of the input pen 1 or the shaft cylinder 10 and the length L1 of the connecting portion 121. For example, the axial length L2 of the tip portion 122 is 0.5 mm to 5 mm.

[0060] <Method for manufacturing pen tip> An example of the method for manufacturing the pen tip of the present embodiment will be described. Note that the method for manufacturing the pen tip broadly encompasses all embodiments having the specific matters of the invention, and the pen tip according to the present embodiment should not be construed as being limited to the manufacturing method described below.

[0061] The method for manufacturing the pen tip according to the present embodiment is not particularly limited. For example, by adopting a method including the following steps (a) to (c), the pen tip according to the present embodiment can be preferably manufactured.

[0062] (a) Kneading step of kneading a raw material containing a filler and a binder to prepare a mixture. (b) Molding step of molding the mixture to create a molded article. (c) Firing step of firing the molded article to create a core body. Hereinafter, steps (a) to (c) will be described.

[0063] (a) Kneading step First, a raw material containing a filler and a binder is kneaded to prepare a mixture. Specifically, first, the raw materials are blended and then mixed and kneaded. Examples of the raw materials include the filler (e.g., boron nitride) and the binder as described above.

[0064] Examples of the binder include inorganic binders or precursors of inorganic binders. Examples of the inorganic binders include those described above. Also, as the binder, organic binders can be used. Representative examples of the organic binders include various resins. As the resin, water-soluble resins, thermoplastic resins, thermosetting resins, etc. are used, but in addition, substances such as silicone rubber, silicone resin, and tetraethyl silicate can also be used. Further, solvents, plasticizers, etc. can be blended as raw materials.

[0065] The mixture of the extender and the binder is the main component of the core. During mixing, an organic binder, a plasticizer, etc. can be added as necessary. The plasticizer used here is for imparting fluidity to the raw material mixture and making the mixture uniform, and is almost completely removed in the firing process.

[0066] Examples of the organic binder include organic polymers, etc. The organic binder has a function as a reinforcing agent for imparting fluidity, shape retention, handling strength, etc. to the mixture. Preferred examples of the organic polymer include thermoplastic resins and water-soluble resins. Specifically, polyvinyl alcohol, vinyl chloride resin, etc. can be mentioned.

[0067] Examples of the plasticizer include polyethylene glycol, dioctyl phthalate, diisobutyl phthalate, etc.

[0068] Mixing can be performed by a conventionally known mixer, for example, a butterfly mixer, a ribbon mixer, etc. Kneading can be performed by a conventionally known kneader, for example, a kneader, a Banbury mixer, a screw-type extrusion kneader, a vacuum kneader, a twin-screw continuous kneading and extrusion molding machine, etc.

[0069] (b) Forming step, Subsequently, the formed mixture is formed to create a molded product in the shape of a pen tip. The forming method is not particularly limited, and for example, conventionally known forming methods such as extrusion molding, press molding, and injection molding may be used.

[0070] (c) Firing process After drying the obtained formed article as required, it is fired to create a core body. By firing, the organic solvent (organic binder) and resin contained in the above mixture are removed, and the filler and binder are sintered to form a core body. The firing conditions are not particularly limited as long as the material is sintered to form a core body. For example, the maximum temperature can be set to 500 to 1300 °C. Preferably, it is 600 to 800 °C. Also, in order to avoid a rapid temperature change, the temperature during firing can be increased continuously or stepwise. The heating rate in such a case can be, for example, 10 to 100 °C / hr. Preferably, it is 20 to 100 °C / hr. Further, after raising the temperature to the set temperature, it is also preferable to fire at a constant temperature for a certain period of time, for example, about 1 to 10 hours. Preferably, it is 1 to 5 hours. Furthermore, these conditions can be arbitrarily combined according to the purpose.

[0071] Note that in this embodiment, a processing step may be performed after the firing step. The processing step is a step of further processing the obtained structure after the firing step into a desired shape. Any method can be used as the processing method in the processing step. Examples of the processing method include any one or more of the group consisting of lathe work, surface grinding, R grinding, and NC machining (Numerical Control machining).

[0072] By the manufacturing method described above, the pen tip according to this embodiment can be manufactured.

[0073] According to the pen tip of this embodiment, high strength, good writing feel, and suppression of dirt adhesion to the input screen can be achieved. Also, since the input pen of this embodiment is provided with a pen tip that is excellent in both strength and writing feel, it can cope with various writing pressures, and even if the input operation time to the input device becomes long, the burden on the user can be reduced, and both the good usability and sustainability can be realized.

[0074] In addition, the input pen of the present embodiment can be used, for example, when performing an input operation on an input device such as a touch pad or a touch panel. Here, the "input device" refers to a so-called pointing device that performs input by physical contact on the input screen, such as a touch pad or a touch panel, and the input method may be any of a capacitance method and an electromagnetic induction method. That is, the input pen of the present embodiment is applicable to any of capacitive and electromagnetic induction input devices, and in particular, can be preferably used for electromagnetic induction input devices.

[0075] As described above, the input pen and the pen tip of the present embodiment have been described. However, the present invention is not limited to the above-described embodiment, and changes in configuration and the like are possible without departing from the gist of the present invention. That is, the present invention may combine the respective configurations described in the above embodiment within the scope not departing from the gist of the present invention, and addition, omission, substitution, and other changes in configuration are possible. Further, the present invention is not limited by the above-described embodiment or the like, and is limited only by the claims.

Example

[0076] Hereinafter, an embodiment of the present invention will be described more specifically while showing examples. Note that the examples shown below are merely examples of the present embodiment, and the input pen and the pen tip according to the present embodiment are not limited to the examples shown below. The present invention can adopt various conditions without departing from the gist of the present invention and as long as the object of the present invention is achieved.

[0077] (Example 1) [Formulation] Boron nitride... 40 parts by mass Silica... 30 parts by mass Polyvinyl alcohol... 30 parts by mass Water...... 100 parts by mass

[0078] The above-mentioned compound was kneaded, and the obtained kneaded material was extruded through a die with a diameter of φ1 to obtain a molded product. This molded product was heated to 600°C at a heating rate of 20°C / hour in nitrogen gas, held at 600°C for 1 hour, and then heated to 650°C at 50°C / hr in an oxidizing atmosphere and fired at 650°C for 1 hour to obtain a pen tip (porosity: 2%). After firing, the molded product was subjected to R grinding to impart a curvature radius R of 0.75 mm to the tip (contact surface) of the pen tip. Hereinafter, in Example 2 to Comparative Example 2 as well, a curvature radius R of 0.75 mm was similarly imparted.

[0079] (Example 2) [Compound] Boron nitride... 40 parts by mass Silica... 30 parts by mass Acrylic resin... 30 parts by mass

[0080] The above-mentioned compound was heated and kneaded, and the obtained kneaded material was extruded through a die with a diameter of φ1 to obtain a molded product. This molded product was heated to 600°C at a heating rate of 20°C / hour in nitrogen gas, held at 600°C for 1 hour, and then heated to 650°C at 50°C / hr in an oxidizing atmosphere and fired at 650°C for 1 hour to obtain a pen tip (porosity: 1%).

[0081] (Example 3) [Compound] Boron nitride... 50 parts by mass Silicone resin... 20 parts by mass Polyvinyl alcohol... 30 parts by mass Water......... 100 parts by mass

[0082] The above-mentioned compound was heated and kneaded, and the obtained kneaded material was extruded through a die with a diameter of φ1 to obtain a molded product. This molded product was heated to 600°C at a heating rate of 20°C / hour in nitrogen gas, held at 600°C for 1 hour, and then heated to 650°C at 50°C / hr in an oxidizing atmosphere and fired at 650°C for 1 hour to obtain a pen tip (porosity: 4%).

[0083] (Comparative Example 1)[Compound] Talc... 65 parts by mass Silica... 25 parts by mass Polyvinyl alcohol... 10 parts by mass Water......... 150 parts by mass

[0084] The above formulation was heat-kneaded, and the obtained kneaded product was extruded through a die with a diameter of φ1 to obtain a molded product. This molded product was heated to 600 °C at a heating rate of 20 °C / hour in nitrogen gas, held at 600 °C for 1 hour, and then heated at 50 °C / hr in an oxidizing atmosphere and fired at 750 °C for 1 hour to obtain a pen tip (porosity: 0%).

[0085] (Comparative Example 2) [Formulation] Boron nitride... 50 parts by mass Silica... 25 parts by mass Polyvinyl alcohol... 15 parts by mass Graphite... 10 parts by mass Water......... 100 parts by mass

[0086] The above formulation was heat-kneaded, and the obtained kneaded product was extruded through a die with a diameter of φ1 to obtain a molded product. This molded product was heated to 600 °C at a heating rate of 20 °C / hour in nitrogen gas, held at 600 °C for 1 hour, and then heated at 50 °C / hr in an oxidizing atmosphere and fired at 650 °C for 1 hour to obtain a pen tip (porosity: 22%).

[0087] [Physical Properties] The arithmetic mean height Sa (μm) of each obtained pen tip was measured using a white light interferometer "NewView" (Zygo Corporation). The measurement conditions were a magnification of ×50, removal of undulations, and the other settings were auto settings.

[0088] As an index representing the strength of the pen tip, the flexural strength was measured. The flexural strength (MPa) was measured using a universal testing machine manufactured by Shimadzu Corporation under the condition of an external support distance of 20 mm in accordance with the method specified in JIS S 6005:2019.

[0089] As the wear amount of the tip, in accordance with the concentration evaluation method of JIS S 6005:2019, using Method A (record type), the writing angle was 75°, the load was 400 gf, and the writing distance was 6 m. The change in the length of the core (core length) when writing on a plastic plate (manufactured by ELECOM Co., Ltd., paper-like anti-reflection film "TB-WIPSFLAPLL") was measured. The core length was obtained by measuring the difference in the length of the tip before and after the measurement test.

[0090] [Evaluation] Regarding the performance of the obtained pen tips, evaluation was carried out by the following method.

[0091] [Writing feel (sensory test result)] Using each of the obtained pen tips, writing was performed on a tablet ("Wacom One" manufactured by Wacom Co., Ltd.), and the writing feel at that time was evaluated by a sensory test. The evaluation criteria are shown below. Note that in this example, the "writing feel" was evaluated from the perspective of a writing feel as if writing on paper with a solid writing instrument. The evaluation results are as shown in Table 1.

[0092] A: Good writing feel: A writing feel like that of a writing instrument was sufficiently obtained. B: Somewhat good writing feel: A writing feel like that of a writing instrument was obtained. C: Poor writing feel: A writing feel like that of a writing instrument was not obtained.

[0093] [Stain on the input screen (writing surface) (writing trace remaining)] Using each of the obtained pen tips, input (writing) was performed on the above-mentioned tablet, and the presence or absence of stains on the screen at that time was visually observed. The evaluation criteria are shown below. The evaluation results are as shown in Table 1.

[0094] A: No stain B: Slightly stained, but not noticeable. (Level with no practical problems) C: Stain present

[0095] [Results] It was confirmed that the pen tip of this embodiment can achieve both excellent writing comfort and suppression of dirt adhesion to the input screen.

[0096]

Table 1

Industrial Applicability

[0097] According to the pen tip of the present invention, it has excellent writing comfort and can suppress the adhesion of dirt to the input screen. Therefore, it has industrial applicability.

Explanation of Reference Numerals

[0098] 1…Input pen, 10…Shaft cylinder, 10a…End part, 20…Pen tip, 21…Connecting part, 22…Tip part, 22a…Contact part

Claims

1. The pen tip of an input pen that performs input by physical contact on the input screen of an input device, a contact surface that contacts the input screen, a tip portion including the contact surface, comprising: the tip portion includes a matrix material and a binder, The pen tip for an input pen, wherein the wear amount of the tip portion is 1 μm or more and 100 μm or less.

2. The pen tip for an input pen according to claim 1, wherein the matrix material is selected from the group consisting of boron nitride, mica, talc, calcium carbonate, and graphite.

3. The pen tip for an input pen according to claim 1 or 2, wherein the arithmetic mean height Sa of the tip portion is 0.4 μm or less.

4. The tip portion has porosity, The pen tip for an input pen according to claim 1 or 2, wherein the porosity of the tip portion is 0 to 15%.

5. The pen tip for an input pen according to claim 1 or 2, wherein the bending strength of the tip portion is 200 MPa or more.

6. The pen tip for an input pen according to claim 1 or 2, wherein the radius of curvature R of the contact surface of the tip portion is 0.1 to 1.5 mm.

7. The pen tip for an input pen according to claim 1 or 2, wherein the input device is an electromagnetic induction type.

8. An input pen that performs input by physical contact on the input screen of an input device, a shaft cylinder that extends axially along a central axis, the pen tip for an input pen according to claim 1, comprising an input pen.

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