Writing instrument

Abstract

In order to provide a writing instrument in which a writing direction can be visually recognized in a broad range at a visual part of a pen tip and which can surely write to end of writing, the writing instrument is endowed with a constitution in which a pen tip is equipped with a porous member as a writing part and a holding member holding the above porous member and having at least one ink guiding part through which an ink contained in a barrel is provided to a writing part held by the holding member which is a visible part enabling to visually recognize a writing direction, wherein an area ratio of the visible part is 40% or more of the pen tip protruding from a tip part of the writing instrument.

Description

TECHNICAL FIELD

The present invention relates to a writing instrument of a type called an underline marker in which an ink in a writing instrument main body is fed to a writing part of a pen tip, more specifically to a writing instrument in which a writing direction can be visually recognized in a broad range at a visual part of a pen tip and which can surely write to end of writing.

BACKGROUND ART

Writing instruments of the respective structures (refer to, for example, patent documents 1 to 5 filed by the present applicant) have so far been known as writing instruments in which a writing direction can be visually recognized at a visual part of a pen tip. Among the above respective patent documents, known as a technique close to that of the present invention is, for example, a writing instrument 1 (refer to, for example, the patent document 1 filed by the present applicant) comprising, as shown in FIG. 25, a pen body 1b which guides an ink supplied from a writing instrument main body 1a and which can reserve it, wherein the pen body 1b described above is equipped with an ink guiding part 1c and a writing part 1d for delivering the ink from the above ink guiding part 1c, and it is equipped as well with a visible part 1e in which a writing direction can be visually recognized right above a holder direction of the above writing part 1d. In particular, the respective pen bodies shown in FIG. 26 and FIG. 27 disclose techniques closest to that of the present invention.

FIGS. 26 (a) and (b) are drawings of the sixth embodiment of a pen body in the writing instrument described in patent document 1 described above. The pen body 2 of the above embodiment is endowed with a structure in which a writing part 2c fixed by a leg part 2b is provided at a front end of a transparent supporting member 2a and in which provided is an ink guiding part 2d comprising an ink guiding groove communicating with a rear end of the leg part 2b in the above writing part 2c and enabling to guide the ink to a prescribed part in an inside of the supporting member 2a described above by a capillary action. Since the supporting member 2a is constituted by a transparent resin and the like, a part 2e becomes a visible part, and a writing direction is visually recognized through an ink flowing in an inside of the supporting member 2a.

Also, FIGS. 27 (a) and (b) show the eighth embodiment of a pen body in the writing instrument described in patent document 1 described above. The pen body 3 of the above embodiment has almost the same structure as that of the pen body of the sixth embodiment in FIG. 26 described above, and a different point thereof resides in a structure in which a window part 3b as a visible part is provided in a supporting member 3a, in which an ink guiding groove 3c is formed bypassing the above window part 3b and in which an ink can be fed to a writing part 3d by a capillary action.

However, in the writing instrument described in patent document 1 described above, taken is a structure in which the ink guiding parts 1c, 3c are provided at both sides of the visible parts 1e, 3b in FIG. 25 and FIG. 27 and in which the writing parts 1d, 3d are provided at a lower part thereof, and therefore an area ratio of the visible part 1e having visibility is actually a level of 30% of the pen tip (pen body) protruding from a tip part of the writing instrument main body. Accordingly, a problem is involved in the point that the satisfactory visibility can not be secured and that it is a little difficult to see the writing direction. If the visible part is enlarged, visibility in the writing direction is broadened, but the writing part is enlarged as well, so that the writing performances as a line marker are damaged.

Also, in the pen body 2 shown in FIG. 26, a writing direction is visually recognized through an ink flowing through an inside of the supporting member 2a, and therefore a problem is involved in the point that it is difficult to see the writing direction when the ink has a deep color. Further, the leg part 2b fixed in an inside of the supporting member 2a does not have visibility, and therefore an area ratio of the visible part having visibility is actually a level of 30% of the pen tip (pen body) protruding from a tip part of the writing instrument main body. Accordingly, the satisfactory visibility can not be secured, and the existing situation is that a pen body having a structure in which a writing direction can further widely be visually recognized is desired.

On the other hand, known as a writing instrument of an ink exhaustion detecting system in which a part of a writing direction in a back of the writing part can be visually recognized and in which an exhaustion sign of an ink can be detected are, for example, a writing instrument 4 of an ink exhaustion detecting system in which as shown in FIGS. 28 (a) and (b), an ink impregnated in an ink occulusion body 4b in an inside of a barrel 4a is fed to a pen tip 4e of a writing part via a feed 4c and an ink guiding part 4d and in which an exhaustion sign of the ink in the ink occulusion body 4b is visually recognized in the ink guiding part 4d described above to thereby detect it, wherein the ink guiding part 4d described above comprises a visible part 4f capable of visually recognizing a writing direction and an ink guiding tube 4g at a side part of the above visible part 4f (refer to, for example, patent document 6 filed by the present applicant) and a writing instrument 5 of an ink exhaustion detecting system in which as shown in FIGS. 29 (a) and (b), an ink impregnated in an ink occulusion body 5b in an inside of a barrel 5a is fed to a pen tip 5e as a writing part via a feed 5c and an ink guiding part 5d and in which an exhaustion sign of the ink in the ink occulusion body 5b is visually recognized in the ink guiding part 5d described above to thereby detect it, wherein the ink guiding part 5d described above comprises a tabular ink guiding part 5g provided with a slit ink passage 5f having a thickness of 0.01 to 1.0 mm in an inside thereof; a visible light transmittance of the ink guiding part 5g in filling the ink is 50% or more; and a writing direction directly under an axis direction of the above ink guiding part 5g can be visually recognized via the ink guiding part 5g (refer to, for example, patent document 7 filed by the present applicant).

However, in the writing instrument 4 shown in FIGS. 28 (a) and (b), the ink guiding tube 4g is thickened (enlarged) in order to surely detect the exhaustion sign, and therefore a little problem is involved in the point that the sufficiently high visibility can not be secured. Further, the existing situation is that, it is not easy to secure a sealing property of the pen tip and obtain a structure in which the ink is exhausted to the end, due to a complicated shape of the ink guiding tube 4g.

Also, in the writing instrument 5 shown in FIGS. 29 (a) and (b), if the ink guiding part is reduced in a thickness to such an extent that the sufficiently high visibility can be secured, the ink flow amount can not be secured. On the other hand, if the ink flow amount is intended to be secured, the sufficiently high visibility can not be secured, and therefore the effective visible part is limited to make it difficult to secure the visibility.

• Patent document 1: Japanese Patent Application Laid-Open No. 52682/2000 (claims, embodiments, FIG. 1, FIG. 11, FIG. 12 and others)
• Patent document 2: Japanese Patent Application Laid-Open No. 253193/2001 (claims, embodiments, FIG. 1 and others)
• Patent document 3: Japanese Patent Application Laid-Open No. 19370/2002 (claims, embodiments, FIG. 1 and others)
• Patent document 4: Japanese Patent Application Laid-Open No. 246606/2005 (claims, embodiments, FIG. 1 and others)
• Patent document 5: Japanese Patent Application Laid-Open No. 256045/2006 (claims, embodiments, FIG. 1 and others)
• Patent document 6: Japanese Patent Application Laid-Open No. 69426/2007 (claims, embodiments, FIG. 1 and others)
• Patent document 7: Japanese Patent Application Laid-Open No. 69427/2007 (claims, embodiments, FIG. 1 and others)

DISCLOSURE OF THE INVENTION

In light of the problems on the conventional techniques described above, the present invention intends to solve them, and an object thereof is to provide a writing instrument comprising a visible part and an ink guiding part, wherein it is provided with a sufficiently high visibility enabling to read surely characters written toward a writing direction, and it can be used to end of writing, and another object is to provide a writing instrument in which a sufficiently high writing flow amount can be secured to end of writing without damaging visibility and which is easy to write and excellent in productivity and durability. Further, an object thereof is to provide a writing instrument in which an ink flow amount is secured to prevent blurring in writing and stabilize a writing flow amount and in which an ink stored in an ink occulusion body can sufficiently be exhausted.

Intense investigations repeated by the present inventors in order to solve the conventional problems described above have resulted in finding that the writing instruments which meet the objects described above are provided by a writing instrument in which a pen tip is equipped with a porous member as a writing part and a holding member holding the above porous member and having at least one ink guiding part for feeding an ink to the writing part, which has a relay porous member for feeding an ink contained in a writing instrument main body to the ink guiding part provided in the holding member described above and in which the holding member described above is a visible part enabling to visually recognize a writing direction, wherein a pen tip structure in which an area ratio of the above visible part is a specific value or more is set, and specific structures are set for an ink feeding mechanism, a structure of the ink guiding part, a structure of the porous member as the writing part and an interfacial structure between the porous member as the writing part and the holding member. Thus, the present invention has come to be completed.

That is, the present invention resides in the following items (1) to (10).

(1) A writing instrument in which a pen tip is equipped with a porous member as a writing part and a holding member holding the above porous member and having at least one ink guiding part for feeding an ink to the writing part, which comprises a relay porous member for feeding an ink contained in a writing instrument main body to the ink guiding part provided in the holding member and in which the holding member is a visible part enabling to visually recognize a writing direction, wherein an area ratio of the above visible part is 40% or more of the pen tip protruding from a tip part of the writing instrument main body.(2) The writing instrument as described in the above item (1), wherein a cross-sectional area of the ink guiding part is less than a cross-sectional area of a holding member side in the writing part.(3) The writing instrument as described in the above item (1), wherein a taper is formed toward a writing part side in the ink guiding part.(4) The writing instrument as described in the above item (1), wherein the ink is fed directly to the ink guiding part.(5) The writing instrument as described in the above item (1), wherein the writing part is inclined to a major axis direction of a main body axis.(6) The writing instrument as described in the above item (1), wherein faces forming the visible part of the holding part are almost parallel.(7) The writing instrument as described in the above item (1), wherein a resin constituting the holding member gets into irregularities of porous member pores from the holding member in a part in which the porous member as the writing part is brought into contact with the holding member to form a holding member resin layer, whereby the porous member and the holding member are fixed.(8) The writing instrument as described in the above item (1), wherein a holding member resin layer is formed in an end face of the ink guiding part at a side of the porous member as the writing part in an interface between the porous member and the holding member, and the holding member resin layer in the above interface is formed toward a whole direction of the end face.(9) The writing instrument as described in the above item (1), wherein a chamfered part is formed in an end face at a side of the porous member to form a contact part for holding the porous member in the holding member.(10) The writing instrument as described in the above item (1), wherein a main body part having a cylindrical part for holding the relay porous member is connected with the holding member; a step part with which the relay porous member can be brought into contact is formed in the cylindrical part; and a gap part is formed between the step part and the relay porous member.

According to the present invention, provided is a writing instrument which is endowed with a sufficiently high visibility making it possible to read more surely characters written toward a writing direction than ever and which can be used to end of writing.

According to the invention as described in claims 2 to 6, further provided is a writing instrument which is excellent in visibility and which can be used to end of writing.

According to the invention as described in claims 7 and 8, further provided is a writing instrument having an excellent durability in which a porous member as a writing part and a holding member having an ink guiding part can surely be fixed and in which a sufficiently large writing flow amount can be secured to end of writing.

According to the invention as described in claim 9, further provided is a writing instrument which is readily assembled and can stabilize a fitting position of a porous member as a writing part and which is excellent durability.

According to the invention as described in claim 10, further provided is a writing instrument in which an ink flow amount is secured to prevent blurring in writing and stabilize a writing flow amount and in which an ink in an ink occulusion body can sufficiently be exhausted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical cross section showing one example of the embodiment of the present invention.

FIG. 2 (a) is a vertical cross section showing one example of a pen tip used for the writing instrument of the present invention; (b) is an A-A line cross section of (a); and (c) is a B-B line cross section of (a).

FIG. 3 (a) is a front view showing a state in which a relay porous member, a porous member as a writing part, a holding member having an ink guiding part and the like are set; (b) is a vertical cross section of (a); and (c) and (d) are a plan view and a perspective drawing of the holding member, respectively.

FIG. 4 (a) is a plan view showing a state in which a porous member as a writing part and a holding member having an ink guiding part are set; (b) is a side view thereof; and (c) and (d) are a front view and a side view, respectively, showing a holding member resin layer in an interface between a porous member and a holding member.

FIG. 5 (a) is a vertical cross section showing one example of an expanded state in which a holding member having an ink guiding part and a relay porous member are set; and (b) is a vertical cross section showing another example of (a).

FIGS. 6 (a) to (d) are front views showing the respective forms of an ink guiding part of a pen tip toward a major axis direction excluding a straight line form.

FIGS. 7 (a) and (b) are continuous from FIG. 6 and are front views showing the respective forms of an ink guiding part of a pen tip toward a major axis direction excluding a straight line form.

FIG. 8 is a drawing of a writing instrument showing another example of the embodiment of the present invention; (a) is a central vertical cross section; and (b) is a central lateral cross section.

FIG. 9 is a drawing showing one example of a rear holder constituting a holder of the writing instrument shown in FIG. 8; (a) is a front view; (b) is a plan view; (c) is a left side view; (d) is a central vertical cross section; and (e) is a central lateral cross section.

FIG. 10 is a drawing showing one example of a front holder of the writing instrument shown in FIG. 8; (a) is a perspective drawing observed from a front side; (b) is a perspective drawing observed from a rear side; (c) is a left side view; (d) is a right side view; and (e) is a central vertical cross section.

FIG. 11 is a drawing showing one example of a pen tip used for the writing instrument shown in FIG. 8; (a) is a front view; (b) is a plan view; (c) is a left side view; (d) is a right side view; and (e) is a base view.

FIG. 12 (a) is a central lateral cross section of a pen tip; and (b) is a perspective drawing of a pen tip observed from a base side.

FIG. 13 is an enlarged view of a central lateral cross section of the pen tip shown in FIG. 12 (a) and is a drawing for explaining a gap part.

FIG. 14 is a drawing showing one example of a porous member as a writing part used for a pen tip of the writing instrument shown in FIG. 8; (a) is a plan view; (b) is a front view; (c) is a left side view; (d) is a right side view; and (e) is a base view.

FIG. 15 is a drawing showing one example of a holding member for holding a porous member as a writing part shown in FIG. 8; (a) is a front view; (b) is a plan view; (c) is a left side view; and (d) is a right side view.

FIG. 16 is a drawing showing one example of a holding member for holding a porous member as a writing part shown in FIG. 8; (a) is a central lateral cross section; (b) is a base view; and (c) is a central lateral cross section.

FIG. 17 is a drawing showing one example of a state in which a cap member is removed from the writing instrument shown in FIG. 8; (a) is a front view; (b) is a plan view; (c) is a left side view; (d) is a right side view; and (e) is a back view.

FIG. 18 is a drawing showing one example of a state in which a cap member is removed from the writing instrument shown in FIG. 8; (a) is a perspective drawing observed from a front side; and (b) is a perspective drawing observed from a rear side.

FIG. 19 is a drawing showing one example of a state in which a cap member is put on the writing instrument shown in FIG. 8; (a) is a front view; (b) is a plan view; (c) is a left side view; and (d) is a right side view.

FIG. 20 is a drawing showing one example of a state in which a cap member is put on the writing instrument shown in FIG. 8, and it is a front view showing a state in which the writing instrument is put as it is on a plane of a desk with a cap member turned downward.

FIG. 21 is a drawing showing one example of a cap member of the writing instrument shown in FIG. 8; (a) is a perspective drawing observed from a front side; (b) is a left side view; (c) is a central vertical cross section; and (d) is a central lateral cross section.

FIG. 22 is an enlarged central lateral cross section showing another form of the pen tip shown in FIG. 12 (a).

FIG. 23 is a front view showing the respective dimensions of a pen tip used for the writing instruments in the examples of the present invention and the comparative examples.

FIG. 24 is an enlarged central lateral cross section showing a form of a pen tip having no gap part which is used in a reference example.

FIG. 25 is a vertical cross section of a writing instrument showing one example of a conventional writing instrument.

FIGS. 26 (a) and (b) are a front view and a lateral cross section showing one example of a pen tip in the conventional writing instrument shown in FIG. 25.

FIGS. 27 (a) and (b) are a front view and a lateral cross section showing another example of a pen tip in the conventional writing instrument shown in FIG. 25.

FIGS. 28 (a) and (b) are a lateral cross section of a writing instrument showing one example of a conventional writing instrument and a lateral cross section showing one example of a pen tip in the writing instrument.

FIGS. 29 (a) and (b) are a lateral cross section of a writing instrument showing one example of a conventional writing instrument and a lateral cross section showing one example of a pen tip in the writing instrument.

EXPLANATION OF NUMERALS

Description of the Preferred Embodiments

The embodiments of the present invention shall be explained below in detail.

FIG. 1 is a vertical cross section showing one example of the embodiment of the writing instrument of the present invention, and FIG. 2 is a drawing showing a pen tip; (a) is a vertical cross section; (b) is an A-A line cross section of (a); and (c) is a B-B line cross section of (a).

The writing instrument A of the present embodiment is a writing instrument of a marking pen type, and it is equipped, as shown in FIG. 1, with a barrel 10 which is a writing instrument main body, an ink occulusion body 20, a relay porous member 30, a pen tip 40 and a plug 10a.

The barrel 10 is formed by, for example, a thermoplastic resin, a thermosetting resin, glass and the like, and it comprises a main body part 111 accepting the ink occlusion body 20 impregnated with an ink for writing and a front holder 15 for fixing the pen tip 40.

The ink occulusion occlusion body 20 is impregnated with an ink for writing, such as an aqueous ink and an oil-based ink, and it comprises, for example, fiber bundles comprising one kind of or combination of two or more kinds of natural fibers, animal hair fibers, polyacetal base resins, acryl base resins, polyester base resins, polyamide base resins, polyurethane base resins, polyolefin base resins, polyvinyl base resins, polycarbonate base resins, polyether base resins, polyphenylene base resins and the like, materials obtained by processing fiber bundles such as felts and porous materials such as sponges, resin particles, and sintered matters. The above ink occlusion body 20 is accepted in the main body part 111 of the barrel 10.

A rear end side opening part of the barrel 10 described above is sealed by the plug 10a formed by the same material as that of the barrel 10 or another synthetic resin-made material.

An ink composition used shall not specifically be restricted, and in an underline pen and the like, fluorescent pigments, for example, Basic Violet 11, Basic Yellow 40 and the like can be contained in an ink.

The relay porous member 30 is a relay feed for feeding an ink in the ink occlusion body 20 to an ink guiding part 50 provided in a holding member 55 described later, and it comprises, as is the case with the ink occlusion body 20, feeds having continuous pores (passages), such as fiber bundles, fiber bundle feeds obtained by processing fiber bundles including felts and the like, hard sponges, resin particle porous bodies comprising resin particle sintered bodies and the like, and sliver feeds. It shall not specifically be restricted in a form thereof, a structure thereof and the like as long as an ink impregnated in the ink occlusion body 20 can be fed to the ink guiding part 50 provided in the holding member 55 via the relay porous member 30. A cross-sectional form of the above relay porous member 30 includes, for example, forms of a circle, an ellipse, a square, a rectangle, a trapezoid, a parallelogram, a lozenge, a semicircle and a semilunar form, and in the present embodiment, the cross-sectional form is circular. The relay porous member 30 in the present embodiment takes, as shown in FIG. 1, a structure in which it is held by a supporting member 35 interfit in the front holder 15.

The pen tip 40 is equipped, as shown in FIG. 1 and FIG. 2, with a porous member (pen feed) 45 as a writing part and the holding member 55 holding the above porous member 45 and having the ink guiding part 50 for feeding an ink to the writing part.

The porous member 45 as the writing part in the present embodiment is fixed in a front part of the holding member 55, and it comprises, for example, parallel fiber bundles comprising one kind of or combination of two or more kinds of natural fibers, animal hair fibers, polyacetal base resins, polyethylene base resins, acryl base resins, polyester base resins, polyamide base resins, polyurethane base resins, polyolefin base resins, polyvinyl base resins, polycarbonate base resins, polyether base resins, polyphenylene base resins and the like, fiber feeds obtained by processing fiber bundles such as felts or subjecting these fiber bundles to resin processing and porous matters (sintered feeds) obtained by sintering various plastic powders and the like.

A form of the porous member 45 as a writing part includes, for example, forms such as a chisel form, a shell form, a cylinder, an elliptical cylinder, a cube, and a cuboid in terms of an appearance form, and it includes such as a trapezoid, a parallelogram, a lozenge, a semicircle, and a semilunar form in terms of a cross-sectional form. In the present embodiment, it is a chisel form. The chisel form is a form in which an inclined plane is formed at a tip toward a central line of a pen holder and in which the inclined plane is flat.

Also, the porous member 45 as the writing part inclines preferably at an angle of 40 to 90° toward a major axis direction of a main body axis so that it is an inclination at which writing is easy, and it is an inclination of 75° in the present embodiment.

A form, an inclination and the like of the porous member 45 as the writing part are suitably set in keeping with usability in writing and the like. Also, the porous member 45 as the writing part has a large drawn line width, and the writing part has a drawn line width of preferably 2 mm or more, more preferably 3 mm or more.

The holding member 55 of the present embodiment is constituted from materials having visibility, for example, materials such as PP, PE, PET, PEN, nylon (including amorphous nylons and the like in addition to conventional nylons such as 6 nylon and 12 nylon), acryl, polymethylpentene, polystyrene, and ABS, and it is constituted preferably from materials having a visible light transmittance of 50% or more. When materials having a visible light transmittance of less than 50% are used, characters written toward a writing direction can not effectively be visually recognized in a certain case, and therefore it is not preferred. Materials having a visible light transmittance of 50% or more are preferred in order to make it possible to exert further better visual recognition function, and materials having a visible light transmittance of 80% or more make it possible to visually recognize characters further better. The visible light transmittance can be determined by measuring a reflectance by means of a multi-illuminant colorimeter.

The above holding member 55 can be constituted from one kind of the respective materials described above, or two or more kinds of the materials in terms of further enhancing the durability and the visibility. When it is constituted from two or more kinds of the materials, at least one of them is preferably the material having a visible light transmittance of 50% or more, and the holding member 55 can be molded by various molding methods such as injection molding and blow molding.

At least one ink guiding part 50 for feeding an ink to the writing part is provided in an inside of the holding member 55 described above, and in the present embodiment, one ink guiding part 50 is provided, as shown in FIGS. 2 (a) and (c), in the center of a longitudinal direction in the form of passing through the holding member in terms of maximizing an area ratio of a visible part and feeding efficiently the ink to the porous member as the writing part.

A form, a structure, a size and the number of the above ink guiding part 50 can suitably be selected as long as set is a structure in which an ink impregnated in the ink occulusion body 20 accepted in the writing instrument main body can be fed directly to the ink guiding part via the relay porous member 30 described above.

From the viewpoint of maximizing the effects of the present invention, a length W of the ink guiding part 50 in a cross section width direction is preferably less than 40%, more preferably 1 to 30% of a major axis length X of the pen tip. Also, a cross-sectional area of the ink guiding part 50 is preferably less than a cross-sectional area of the writing part at a holding member side or less than a cross-sectional area of the relay porous member 30 at a holding member side.

In particular, from the viewpoint of securing a sufficiently high writing flow amount without damaging visibility of the holding part, the ink guiding part 50 has a tubular form in which a length in a lateral direction of the ink guiding part is preferably 3 mm or less, more preferably 0.1 to 2.5 mm and in which a diameter is 0.1 to 3.0 mm, preferably 0.2 to 2.5 mm and more preferably 0.2 to 2.0 mm.

Also, the sum of a cross-sectional area of the ink guiding part 50 in the holding member 55 is 0.01 to 7 mm², preferably 0.03 to 5 mm² and more preferably 0.03 to 4 mm².

Further, a taper is preferably formed toward a writing part 45 side in the ink guiding part 50, and only one taper, though may be a plurality of two or more tapers, is preferably provided in a direction of 0 to 30° toward a major axis direction of a main body axis.

Also, a form of the ink guiding part 50 is preferably straight to a major axis direction, and it can be as well, as described later, a form which is liable to be visually recognized, such as a V form, an X form, a Y form, a spiral form, an inverted V form and an inverted Y form.

In the present embodiment, from the viewpoints of protecting the porous member as the writing part and securing a sealing property thereof, a flange 51 is integrally formed at a relay porous member 30 side of the holding member 55 by the same material as that of the holding member, and an aperture part 52 which is larger than the ink guiding part 50 is formed in a concentric circle form at a tip of the ink guiding part 50.

A method for forming the ink guiding part 50 having the structure described above includes, for example, a method in which a resin is inserted into a die equipped with a bar-like member and the like for forming an ink guiding part and molded by the respective resin molding methods such as injection molding and blow molding and in which the molded matter is then removed from the die to form the ink guiding part 50 in the holding member 55, a method in which the holding member 55 is molded and in which the ink guiding part 50 is then formed by drilling and laser processing and the like and a method in which the holding member 55 is divided into two members, in which grooves for forming an ink guiding part are formed in the respective members and in which they are then integrated by adhesion, fusion and the like to form the ink guiding part 50 in the holding member 55. It can be formed by the same methods as described in the prior art documents.

In the present invention, the ink guiding part 50 provided in an inside of the holding member 55 described above has preferably a visible light transmittance of less than 50% in a state in which an ink for writing described later is accepted therein, and preferably it does not function as a visible part and preferably does not make it possible to visually recognize a writing direction effectively. If an ink can be visually recognized in a state in which the ink is accepted in the ink guiding part 50, the color components and the like of the ink are limited in use, and ink colors corresponding to the needs are not available, so that it is not preferred. In the above case, a pipe colored with almost the same color as that of the ink for writing may be inserted into the ink guiding part 50 to make it possible to readily recognize the ink color.

Also, parts other than the ink guiding part 50 in the holding member 55 are faces for forming a visible part, and they are preferably almost parallel faces in order to visually recognize a writing direction effectively. The writing direction can be enlarged and visually recognized as well by providing the visible part with a lens face.

In the present invention, the porous member 45 as the writing instrument described above is adhered to the holding member 55 having the ink guiding part 50 by allowing the resin for forming the holding member to be inserted into irregularities in pores of the porous member 45 from the holding member 55 at a part at which the porous member 45 is brought into contact with the holding member 55 to form a holding member resin layer from the viewpoint of firmly fixing the porous member 45 in a state of providing it with a sealing performance, whereby the porous member 45 and the holding member 55 are preferably fixed.

The materials for forming the porous member 45 and the holding member 55 are selected preferably from resins having different solubilities in a solvent. For example, in a case in which the porous member 45 is a polyethylene-made sintered feed and in which the holding member is made of acryl, organic solvents such as alcohols, esters (such as butyl acetate), ethers, ketones (such as acetone), glycol ethers, alicyclic hydrocarbons, aliphatic hydrocarbons, chloro-substituted aliphatic hydrocarbons (such as dichloromethane), aromatic hydrocarbons, and chloro-substituted aromatic hydrocarbons are used as the solvent since a difference in a solubility parameter (SP value) between the porous member resin and the holding member resin can be set to 0.5 or more, whereby the porous member 45 as the writing instrument described above and the holding member 55 having the ink guiding part 50 can be fixed.

A holding member resin layer (hereinafter the holding member resin layer in an interface is referred to as an adhesion face) is formed preferably in an end face of the ink guiding part 50 at a writing part porous member 45 side in an interface between the porous member 45 and the holding member 55, and the above adhesion face is preferably formed toward a whole direction of the end face in a length of 0.5 mm or more, more preferably 0.8 to 3 mm.

The above adhesion face can be formed in any of a plane, a curved surface and a bent part, and the adhesion face is preferably formed in an end face of the ink guiding part 50 at a writing part porous member 45 side in a length of 0.5 mm or more, more preferably 0.8 to 3 mm over a whole periphery of the above end face.

Also, the holding member resin layer on the adhesion face is preferably formed in a depth of 1 to 1000 μm, more preferably 10 to 800 μm toward an inside of the porous member 45, and a surface of a local peak in a contact part of the holding member 55 brought into contact with the porous member 45 in the writing part is preferably turned into a satin finished surface state by surface texturing and the like.

FIG. 3 and FIG. 4 show an embodiment of an adhesion structure between the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50.

In FIG. 3, (a) and (b) are a front view and a vertical cross section showing a state in which the relay porous member 30, the supporting member 35, the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50 are set, and (c) and (d) are a plan view and a perspective drawing of the holding member 55. In FIG. 4, (a) is a plan view showing a state in which the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50 are set; (b) is a side view thereof; and (c) and (d) are a front view and a side view showing a holding member resin layer 46 in an interface between the porous member 45 and the holding member 55.

In the above embodiment, rib members 56 are provided, as shown in FIG. 3 (d), on two or more side faces of the porous member 45 in the writing part on an upper part of the holding member 55 from the viewpoint of firmly fixing the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50, and in the present embodiment, two rib members are provided.

Also, two faces in insides of side faces of the rib members 56 and a base part excluding an aperture part of the ink guiding part 50 are, as shown in FIG. 3 (d), adhesion faces between the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50, and a surface of a local peak at a contact part of the holding member 55 brought into contact with the porous member 45 in the writing part is preferably turned into a satin finished surface state by surface texturing and the like.

In the above embodiment, the porous member 45 and the holding member 55 can be fixed by double molding.

In the present embodiment thus constituted, the porous member 45 as the writing instrument described above is adhered to the holding member 55 having the ink guiding part 50 by allowing the resin for forming the holding member to be inserted into irregularities in pores of the porous member 45 from the holding member 55 at a part at which the porous member 45 is brought into contact with the holding member 55 to form a holding member resin layer 46 on the base part, whereby the porous member 45 as the writing part and the holding member 55 having the ink guiding part 50 can surely be fixed, and a writing instrument which can secure a sufficiently high writing flow amount to end of writing and which is excellent in durability is obtained.

Also, in the present invention, the relay porous member 30 can be adhered to the holding member 55, as is the case with the embodiment described above, by forming a holding member resin layer.

To be specific as shown in FIG. 5 (a), a relay porous member 30 side adhesion face is formed in any of a plane, a curved surface and a bent part, and a holding member resin layer (hereinafter referred to as “a relay porous member side adhesion face”) is formed in an end face at a relay porous member 30 side of the ink guiding part 50 in a thickness of 0.5 mm or more over a whole periphery of the relay porous member 30 in an interface between the holding member 55 and the relay porous member 30 inserted into a supporting member 35 of the above holding member 55. A circumferential holding member resin layer 31 on the relay porous member 30 side adhesion face is formed in a depth of 1 to 1000 μm toward a porous member inside, and a surface of a local peak in a contact part of the holding member 55 brought into contact with the relay porous member 30 is turned into a satin finished surface state by surface texturing and the like.

In the present embodiment thus constituted, the relay porous member 30 is adhered to the holding member 55 having the ink guiding part 50 by allowing the resin for forming the holding member to be inserted into irregularities in pores of the relay porous member 30 from the holding member 55 at a part at which the relay porous member 30 is brought into contact with the holding member 55 to form a holding member resin layer 31, whereby the relay porous member 30 and the holding member 55 having the ink guiding part 50 can surely be fixed; a sufficiently high writing flow amount can be fed to the ink guiding part 50; and the writing instrument is excellent in durability. Also, the holding member resin layer 31 may be formed, as shown in FIG. 5 (b), in the whole of a part into which the relay porous member 30 is pressed and in which the supporting member 35 is brought into contact with the relay porous member 30.

In the writing instruments shown in FIG. 1 to FIG. 5 of the present embodiment, the pen tip 40 is equipped, as described above, with the porous member 45 as the writing part and the holding member 55 holding the above porous member 45 and having at least one ink guiding part 50 for feeding an ink to the writing part, and it has the relay porous member 30 for feeding the ink contained in the writing instrument main body 10 to the ink guiding part 50 provided in the holding member 55. The holding member 55 described above is constituted by a material having visibility, and therefore in the above holding member 55, a whole face (whole part) other than the ink guiding part 50 is a visible part in which a writing direction can be visually recognized. An area ratio of the visible part can be first controlled to 40% or more of the pen tip protruding from a tip part of the writing instrument main body 10 by employing the above structure, and an area ratio of the visible part on a side face of the holding member 55 in the pen tip is preferably controlled as well to 40% or more. Further, an area ratio of the visible part can be controlled to 50% or more by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55 and setting a length, a diameter and a cross-sectional area of the ink guiding part 50 in a lateral direction to the preferred ranges described above, and provided is a writing instrument which can be endowed with a sufficiently high visibility making it possible to read characters written toward a writing direction more surely than ever and which can be used to end of writing. In particular, an ink can efficiently be fed evenly to the porous member 45 as the writing part by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55, and therefore a writing instrument which can be used to end of writing is provided.

Also, the form in which a writing direction is liable to be determined and in which the writing instrument is very liable to write is obtained by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55.

Further, providing the rib members 56 on an upper part of the holding member 55 makes it possible to draw straight lines without staining a ruler when drawing them with the ruler.

Further, an ink can efficiently be fed to the porous member 45 as the writing part by employing a mechanism in which a liquid is fed directly to the ink guiding part 50. When a porous member is used as the ink guiding part 50, a suitable ink flow amount is not obtained in a certain case.

In the embodiment described above, the ink guiding part 50 having a form in which it is formed linearly toward a major axis direction is described in detail, and a form of the ink guiding part 50 at the pen tip 40 can be turned into a form which is liable to be visually recognized by employing the respective forms shown in FIG. 6 (a) to (d) and FIGS. 7 (a) and (b). In FIG. 6 and FIG. 7, the same numerals shall be given to the same constitutions as in the embodiments described above to omit the explanations thereof.

FIG. 6 (a) shows a V form used as a form of the ink guiding part 50; FIG. 6 (b) shows an X form; FIG. 6 (c) shows a Y form; FIG. 6 (d) shows a spiral form; FIG. 7 (a) shows an inverted V form; and FIG. 7 (b) shows an inverted Y form.

Also, in the embodiment described above, two rib members 56 are provided, and three rib members may be provided. Further, they can be provided as well on a whole periphery (four directions) of the porous member.

FIG. 8 to FIG. 21 are the respective drawings showing different examples of the embodiments of the writing instruments in the present invention, wherein FIGS. 8 (a) and (b) are a central vertical cross section and a central lateral cross section in the whole of the writing instrument. FIG. 9 to FIG. 16 are the respective drawings showing a rear holder, a front holder, a pen tip and the respective parts of the pen tip which constitute the writing instruments. FIG. 17 and FIG. 18 are the respective drawings showing the writing instrument of a state in which a cap member is removed, and FIG. 19 and FIG. 20 are the respective drawings showing the writing instrument of a state in which a cap member is attached. FIG. 21 is a drawing of the cap member. In FIGS. 8 (a) and (b), shown are two embodiments of a state in which a cap member is attached to an ordinary front holder side and a state in which it is removed therefrom and attached to a rear barrel side of the writing instrument main body.

The same numerals shall be given to the respective parts (a barrel, an ink occulusion body, a relay porous member and pen tip parts) having the same structures, characteristics and qualities as those of the writing instrument A of the embodiment described above to omit or simplify the explanations thereof.

The writing instrument B of the above embodiment is a writing instrument of a marking pen type, and it is equipped, as shown in FIG. 8, with a barrel 10, an ink occulusion body 20, a relay porous member 30, a pen tip 40 and a cap member 60 which constitute a writing instrument main body.

The barrel 10 is formed by, for example, a thermoplastic resin, a thermosetting resin, glass and the like, and it has, as shown in FIG. 8 to FIG. 10, a closed-bottom cylindrical rear barrel 11 for accepting the ink occulusion body 20 impregnated with an ink for a writing instrument and a front holder 15 for fixing the pen tip 40.

The rear barrel 11 is molded, for example, in a long closed-bottom elliptically cylindrical form by using a synthetic resin such as PP, and it functions as a main body (barrel) of the writing instrument. The above rear barrel 11 is provided, as shown in FIG. 9 (a) to (e), with a holding member 13 comprising holding pieces 12, 12—for holding a rear end part of the ink occulusion body 20 inside of a rear end, and the whole of the rear barrel and the front holder described later are molded in an opaque or transparent (and translucent) state. Any of them may be employed from the viewpoint of the appearance and the utility. Also, a structure in which the front holder 15 is fixed in an aperture part 14 of the rear barrel 11 by interfitting and the like is taken.

The front holder 15 has, as shown in FIG. 10 (a) to (e), a circular interfitting part 16 interfitting with the aperture part 14 of the rear barrel 11 at a rear side and a shoulder part 17 and a cylindrical inserting part 18 fixing a main body part 41 of the pen tip 40 at a front side, and a holding member 19 comprising holding pieces 19a, 19a—for holding a front end part of the ink occulusion body 20 is provided in the interfitting part 16 described above. Inserting projection parts 18a, 18b are provided on an inner circumference of the inserting part 18 described above. The front holder 15 of the above structure is molded, for example, by a synthetic resin comprising PP and the like.

The ink occulusion body 20 is impregnated with an ink for a writing instrument such as an aqueous ink and an oil-based ink, and it comprises fiber bundles, materials obtained by processing fiber bundles such as felts and porous materials such as sponges, resin particles, and sintered matters which are the same as in the embodiment described above. The above ink occulusion body 20 is accepted and held in the rear barrel 11 which is a main body of the barrel 10. Also, an ink composition used shall not specifically be restricted as is the case with the writing instrument A of the embodiment described above.

Also, the relay porous member 30 which is a feeder is a feed for relaying which supplies an ink in the ink occulusion body 20 to an ink guiding part 50 provided in a holding member 55 described later, and it has a structure in which it is penetrated into a concave part at a front side of the ink occulusion body 20. The above relay porous member 30 is constituted in the same structure as in the writing instrument A of the embodiment described above.

The pen tip 40 is equipped, as shown in FIG. 11 to FIG. 16, with a porous member (pen feed) 45 as a writing part and a holding member 55 having an ink guiding part 50 for feeding an ink to the writing part, and the holding member 55 is connected with a main body part 42 having a cylindrical part 41 holding a relay porous member at a rear side. A flange part 43 is provided in an outer circumference of the main body part 42, and an inserting holding part 41a for inserting and holding the relay porous member 30 is provided in an inlet of the cylindrical part 41.

A circular step part 48 with which an end face of the relay porous member 30 at a front side thereof can be brought into contact is formed, as shown in FIG. 13, in a rear position than a rear end of the ink guiding part 50 at a front side of the cylindrical part 41, and a gap part 49 is formed between the above step part 48 and the relay porous member 30. The above gap part 49 has such a distance that an end face of the relay porous member 30 is not brought into contact with the step part 48, and a length Y in a longitudinal direction falls in a range of preferably 0<Y≦2 mm. In the present embodiment, the gap part is constituted from a gap part of Y=1 mm. Further, in the present embodiment, a convex part 49a of an opening type which is smaller than a diameter of the relay porous member 30 and which is larger than a diameter of the ink guiding part 50 is formed between the step part 48 and the ink guiding part 50.

The pen tip 40 of the above structure is endowed with a structure in which an ink from the ink occulusion body 20 can be continuously fed to the relay porous member 30, the gap part 49, the convex part 49a, the ink guiding part 50 and the porous member (pen feed) 45 as the writing part by a capillary action. A base of the main body part 42 is a flat face chamfered part 44, and inserting convex parts 42a, 42b for inserting into an inserting part 18 of a front holder 15 are provided in an outer circumference of the main body part 42.

Also, rib members 56, 56 holding the pen feed 45 are provided on both side faces at an upper side of the holding member 55, and a base part 57 brought into contact with a base of the pen feed 45 is provided between the above rib members 56, 56. An outlet of the ink guiding part 50 is formed in a central part of the above base part 57. Further, a contact part 58 with which a front end face of the pen feed 45 is brought into contact is provided on one end face of the rib members 56, 56, and the other end face is an inlet for inserting the pen feed 45.

A whole part of the pen tip 40 thus constituted or the holding member 55 described later is constituted, as is the case with the writing instrument A of the embodiment described above, from materials having visibility, for example, materials such as PP, PE, PET, PEN, nylon (including amorphous nylons and the like in addition to conventional nylons such as 6 nylon and 12 nylon), acryl, polymethylpentene, polystyrene, and ABS, and it is constituted preferably from materials having a visible light transmittance of 50% or more. They can be molded, as is the case with the writing instrument A of the embodiment described above, by various molding methods such as injection molding and blow molding.

The porous member (pen feed) 45 as the writing part of the present embodiment is fixed at a front part of the holding member 55, and a form thereof includes, for example, forms such as a chisel form, a shell form, a cylinder, an elliptical cylinder, a cube, a cuboid, and other forms, as is the case with the writing instrument A of the embodiment described above, in terms of an appearance form, and in the present embodiment, it is a chisel form.

In the above pen feed 45, an inclined plane 46a and chamfered parts 47, 47 in holding the ink guiding part 50 are formed on one end face.

Also, the pen feed 45 as the writing part inclines preferably toward a major axis direction of the main body axis at an angle of 40 to 90° so that an inclination in which the writing instrument is liable to write is provided, and in the present embodiment, the pen feed is mounted at an inclination of 75°.

A form, an inclination and the like of the pen feed 45 as the writing part are suitably set according to the usability such as writing. Also, the pen feed 45 as the writing part has a large drawn line width, and the writing part has a drawn line width of preferably 2 mm or more, more preferably 3 mm or more.

At least one ink guiding part 50 for feeding an ink to the pen feed 45 as the writing part is present in an inside of the holding member 55 described above, and in the present embodiment, one ink guiding part 50 is provided, as shown in FIG. 11 and FIG. 12, in the center of a longitudinal direction in a passing-through form from the viewpoints of exerting an area ratio of the visible part to the utmost and feeding efficiently an ink to the porous member as the writing part.

A form, a structure, a size, the number and the like of the above ink guiding part 50 can suitably be selected as long as it has a structure in which an ink impregnated in the ink occulusion body 20 provided in the writing instrument main body can be fed directly to the ink guiding part via the relay porous member 30 and the gap part 49.

A length W of the ink guiding part 50 in a cross-sectional width direction is, as is the case with the writing instrument A of the embodiment described above, preferably less than 40%, more preferably 1 to 30% of a major axis length X of the pen tip from the viewpoints of exerting the effects of the present invention to the utmost, and a cross-sectional area of the ink guiding part 50 is preferably less than a holding member side cross-sectional area of the writing part or less than a holding member side cross-sectional area of the relay feed 30.

In particular, a length W of the ink guiding part 50 in a lateral direction is, as is the case with the writing instrument A of the embodiment described above, preferably 3 mm or less, more preferably 0.1 to 2.5 mm from the viewpoint of securing a sufficiently high writing flow amount without damaging visibility of the holding member, and it has preferably a form of a tube having a diameter of preferably 0.1 to 3.0 mm, more preferably 0.2 to 2.5 mm.

Also, a sum of a cross-sectional area of the ink guiding part 50 in an inside of the holding member 55 is preferably 0.01 to 7 mm², more preferably 0.03 to 5 mm².

Further, in the ink guiding part 50, a taper is preferably formed toward the pen feed 45 as the writing part, and one taper is preferably provided in a direction of 0 to 30° toward a major axis direction of the main body axis.

The ink guiding part 50 having the structure described above can be formed by the same method as in the writing instrument A of the embodiment described above.

In the above embodiment, the ink guiding part 50 provided in an inside of the holding member 55 described above has, as is the case with the writing instrument A of the embodiment described above, preferably a visible light transmittance of less than 50% in a state in which an ink for writing described later is accepted therein, and preferably it does not function as a visible part and does not make it possible to visually recognize a writing direction effectively. If an ink can be visually recognized in a state in which the ink is accepted in the ink guiding part 50, the color components and the like of the ink are limited in use, and ink colors corresponding to the needs are not available, so that it is not preferred.

Also, the holding member 55 other than the ink guiding part 50 is faces for forming the visible part, and they are preferably almost parallel faces in order to visually recognize a writing direction effectively. The writing direction can be enlarged and visually recognized as well by providing the visible part with a lens face.

In the writing instrument B of the above embodiment, the porous member (pen feed) 45 as the writing part described above can readily be mounted to the holding member 55 in a manner described below as compared with mounting of the porous member as the writing part in the writing instrument A of the embodiment described above.

To be specific, a chamfered part 47, 47 side of the pen feed 45 shown in FIG. 14 is turned to the front; the pen feed 45 is inserted from an aperture part (inlet side) in an opposite side of the contact part 58 at an upper side of the holding member 55 while bringing a bottom of the pen feed 45 into contact with the inner faces and the bottom part 57 of the ribs 56, 56, whereby a front part 48 of the pen feed 45 is brought into contact with the contact part 58, and the pen feed 45 can readily be mounted to an upper face part of the holding member 55.

Conventionally, in mounting the pen feed 45 as the writing part to the holding member 55, the rib faces 56, 56 of the holding member 55 and the pen feed 45 itself are liable to be deformed when the pen feed 45 is not chamfered, and it is difficult to mount the pen feed 45 to the holding member 55. In the present embodiment, however, the pen feed 45 can readily be assembled in holding the ink guiding part 50 and the pen feed 45 by forming the chamfered parts 47, 47 in an end face of the pen feed 45 and further forming the contact part 58 for holding the pen feed 45 in the holding member 55, and a mounting position of the pen feed can be stabilized.

In mounting the pen feed 45 described above, the resin for forming the holding member is inserted, as is the case with the writing instrument A of the embodiment described above, from the holding member 55 into irregularities in pores of the porous member 45 at a part at which the porous member 45 is brought into contact with the holding member 55 to form a holding member resin layer from the viewpoint of firmly fixing the porous member 45 in a state of providing it with a sealing performance, whereby the porous member 45 and the holding member 55 are preferably fixed.

In the above case, the porous member 45 and the holding member 55 having the ink guiding part 50 can be fixed in the same manner as in the writing instrument A of the embodiment described above by the materials forming the porous member 45 and the holding member 55.

A holding member resin layer (the holding member resin layer in an interface is referred to as an adhesion face) is preferably formed, as is the case with the writing instrument A of the embodiment described above, in an end face of the ink guiding part 50 at a side of the pen feed 45 as the writing part in an interface between the porous member 45 and the holding member 55, and the above adhesion face is preferably formed toward a whole direction of the end face in a length of 0.5 mm or more, more preferably 0.8 to 3 mm.

The above adhesion face can be formed, as is the case with the writing instrument A of the embodiment described above, in any of a plane, a curved surface and a bent part, and the adhesion face is preferably formed in an end face of the ink guiding part 50 at a writing part pen feed 45 side in a length of 0.5 mm or more, more preferably 0.8 to 3 mm over a whole periphery of the above end face.

Also, the holding member resin layer on the adhesion face is preferably formed in a depth of 1 to 1000 μm, more preferably 10 to 800 μm toward an inside of the pen feed 45, and a surface of a local peak in a contact part of the holding member 55 brought into contact with the pen feed 45 is preferably turned into a satin finished surface state by surface texturing and the like.

FIG. 11 to FIG. 13 are the respective drawings of a state in which the porous member 45 as the writing instrument and the holding member 55 having the ink guiding part 50 are fixed.

FIG. 17 and FIG. 18 are the respective drawings showing one example of a state in which a cap member is removed in the writing instrument B of the above embodiment; FIG. 19 and FIG. 20 are the respective drawings showing one example of a state in which the cap member is attached; and FIG. 21 shows the respective drawings of the cap member.

In the writing instrument B of the above embodiment, the ink occulusion body 20 absorbing an ink, the pen tip 40 which holds the relay feed 30 so that the gap part 49 is formed and which is equipped with the pen feed 45 and the front holder 15 are mounted in order in the rear barrel 11 by interfitting and the like, whereby the writing instrument can readily be produced.

The cap member 60 is detachably mounted in the front holder by interfitting and the like and constituted from an inner cap part 61 protecting the pen tip 45 and a cylindrical outer cap part 62, and it has a structure in which a concave part 63 for enhancing a design property is formed on a surface of the outer cap part 62. Also, an opening face at a front side of the outer cap part 62 is, as shown in FIG. 20, a wide opening face so that it is provided with a structure in which it can be stood on a flat face of a desk and the like, and in the present embodiment, it is an elliptical opening face having a lateral direction length of 1.5 cm, a longitudinal direction length of 2.8 cm and a thickness of 1 mm.

In the writing instrument B of the present embodiment thus constituted, the pen feed 45 can readily be set up into the holding member 55 by forming the chamfered parts 47, 47 in an end face of the pen feed 45 in holding the ink guiding part 50 in the porous member (pen feed) 45 as the writing part and further forming the contact part 58 for holding the pen feed 45 in the holding member 55, and a mounting position of the pen feed 45 can be stabilized.

Also, in the writing instrument B of the present embodiment, the gap part 49, preferably the gap part in which a length Y in a longitudinal direction is 0<Y≦2 mm is formed between the circular step part 48 with which an end face of the relay porous member 30 as a feed can be brought into contact and the feed 30, whereby an ink from the ink occulusion body 20 can be fed continuously and efficiently to the feed 30, the gap part 49 (and the convex part 49a), the ink guiding part 50 and the pen feed 45 by a capillary action, and therefore obtained is the writing instrument in which a suitable ink flow amount is secured to prevent blurring in writing and stabilize a writing flow amount and in which an ink stored in the ink occulusion body can sufficiently be exhausted. Forming further the convex part 49a of an opening type which is smaller than a diameter of the relay porous member 30 and larger than a diameter of the ink guiding part 50 between the step part 48 and the ink guiding part 50 in the above gap part 49 makes it possible to further secure a suitable ink flow amount, further prevent blurring in writing and further enhance stabilization of a writing flow amount.

Also, the pen tip 40 is equipped, as described above, with the pen feed 45 as the writing part and the holding member 55 holding the above pen feed 45 and having at least one ink guiding part 50 for feeding an ink to the writing part, and it has the relay porous member 30 for feeding the ink contained in the ink occulusion body 20 to the ink guiding part 50 provided in the holding member 55. The holding member 55 described above is constituted by a material having visibility, and therefore in the above holding member 55, a whole face (whole part) other than the ink guiding part 50 is, as shown in FIG. 17, FIG. 18 and the like, a visible part in which a writing direction can be visually recognized. An area ratio of the visible part can be 40% or more of the pen tip protruding from a tip part of the front holder 15, and an area ratio of the visible part on a side face of the holding member 55 at the pen tip is controlled as well to 40% or more. Further, an area ratio of the visible part can be controlled to 50% or more by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55 and setting a length, a diameter, a cross-sectional area and the like of the ink guiding part 50 in a lateral direction to the preferred ranges described above, and provided is the writing instrument which can be endowed with a sufficiently high visibility making it possible to read characters written toward a writing direction more surely than ever and which can be used to end of writing. In particular, the ink can efficiently be fed evenly to the porous member 45 as the writing part by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55, and therefore the writing instrument which can be further used to end of writing is provided.

Also, the form in which a writing direction is liable to be determined and in which the writing instrument is liable to write is obtained by forming the ink guiding part 50 in a central part of a longitudinal direction of the holding member 55. Further, providing the rib members 56, 56 on an upper part of the holding member 55 makes it possible to draw straight lines without staining the ruler when drawing them with a ruler.

Further, an ink can efficiently be fed to the porous member 45 as the writing part by employing a mechanism in which a liquid is fed directly to the ink guiding part 50. When a porous member is used as the ink guiding part 50, a suitable ink flow amount is not obtained in a certain case.

In the writing instrument B of the embodiment described above, taken is a structure in which the ink from the ink occulusion body 20 can be continuously fed to the relay porous member 30, the gap part 49, the convex part 49a, the ink guiding part 50 of the holding part 55 and the pen feed 45 by a capillary action, and the convex part 49a may be omitted without providing to feed, as shown in FIG. 22, the ink from the ink occulusion body 20 to the relay porous member 30, the gap part 49, the ink guiding part 50 and the pen feed 45 by a capillary action. As shown in FIG. 24, when the gap part is not formed, securing of a suitable ink flow amount, blurring in writing, stabilization of a writing flow amount and the like are, as is the case with a reference example described later, a little inferior. In FIG. 22 and FIG. 24, constitutions common to that in FIG. 13 are shown by the same numerals to omit explanations thereof.

Also, in the writing instrument B of the embodiment described above, the barrel of the writing instrument main body is formed in an elliptical cross-sectional form, but it may be circular, triangle and polygonal more than square.

Further, in the writing instrument B of the embodiment described above, the writing instrument in which the ink guiding part 50 is formed in a linear form toward a major axis direction is described in detail, but the ink guiding part 50 in the pen tip 40 can be formed as well in the respective forms shown in FIG. 6 (a) to (d) and FIGS. 7 (a) and (b) to make it liable to be visually recognized.

EXAMPLES

Next, the present invention shall be explained in further details with reference to examples and comparative examples, but the present invention shall not be restricted to the examples shown below.

Test Example 1

Examples 1 to 4 and Comparative Examples 1 to 6

A writing instrument equipped with a pen tip having the following composition and an ink were used. The respective sizes shown in the following Table 1 and FIG. 23 were used for the dimensions of a porous member as a writing part, a holding member and an ink guiding part which constitute the respective pen tips. Common ones were used for writing instrument members other than the pen tip and the ink.

Constitution of Pen Tip:

Writing part porous member: PE-made sintered feed, porosity: 60%

Holding member: acryl-made, visible light transmittance: 85% (reflectance was measured by means of a multi-illuminant colorimeter (MSC-5N) manufactured by Suga Test Instruments Co., Ltd. to determine a visible light transmittance, hereinafter the same shall apply).

An area (area ratio) of the visible parts in the respective pen tips was calculated by measuring an actual dimension of the molded article. An area (area ratio) of the visible parts in the respective pen tips is shown in the following Table 1.

Ink guiding part: cylindrical form, the respective diameters described in the following Table 1, a visible light transmittance in a state in which the ink was contained therein: 27% (common)

Constitution of Writing Instrument Members Other than the Pen Tip:

Relay porous member: PET fiber bundle, porosity: 65%, φ4×25 mm

Ink occulusion body: PET fiber bundle, porosity: 85%, φ14×55 mm

Writing instrument main body, plug and cap: polypropylene (PP)-made

The relay porous member, the writing part porous member and the holding member were adhered in the following manner.

The relay porous member and the writing part porous member were adhered by impregnating them with an organic solvent (ethyl acetate) in a state in which the respective porous members were temporarily inserted into the holding member and then drying them.

A porous member of a PET fiber bundle, a porosity: 65% and φ1.5×8 mm was used as the porous member of the ink guiding part in Comparative Example 3.

Comparative Example 5 is based on FIG. 1 (FIG. 28 in the present application) of patent document 6 (Japanese Patent Application Laid-Open No. 69426/2007) which is a conventional technique, and Comparative Example 6 is based on FIG. 1 (FIG. 29 in the present application) of patent document 7 (Japanese Patent Application Laid-Open No. 69427/2007) which is s conventional technique. The pen tips of the materials and the sizes described in each Example 1 of the respective patent documents were used.

Ink Composition, Common:

A fluorescent rosy ink was used as the ink.

	Color material: VC Toner Momo	30	parts by mass
	(manufactured by Mikuni Color Ltd.)
	Wetting agent: glycerin	25	parts by mass
	Preservative: Bioace (manufactured	0.7	part by mass
	by KI Chemical Industry Co., Ltd.)
	Ion-exchanged water	44.3	parts by mass

The respective pen tips having the constitution described above were used to evaluate visibility and an ink flow amount by the following evaluation methods.

The evaluation results thereof are shown in the following Table 1.

Evaluation Method of Visibility:

Writing was carried out on characters, and an extent of seeing an opposite side via the visible part in writing was visually confirmed to evaluate the visibility according to the following evaluation criteria.

Evaluation Criteria of Visibility:

◯: satisfactory visibility; very easy to see, and writable while reading characters written toward a writing direction.

Δ: unsatisfactory visibility; visible to some extent, but have to visually recognize them carefully in order to read characters written toward a writing direction.

x: unsatisfactory visibility; partially visible but invisible in ordinary use.

Evaluation Method of Ink Flow Amount:

The writing instrument was set in an automatic writing equipment to write a straight line on a wood free paper face at a writing angle of 65°, a writing force of 1 N and a speed of 7 cm/s in a distance of 20 m according to JIS 56037, and then a state of the written line was visually confirmed to evaluate the ink flow amount according to the following evaluation criteria.

Evaluation Criteria of Ink Flow Amount:

◯: good writing property and no blurring in the drawn lines.

Δ: unsatisfactory writing property and blurring in the drawn lines.

x: unsatisfactory writing property and marked blurring in the drawn lines.

TABLE 1
			Ink guiding		Visible
	Writing	Holding	part size		part area		Ink
	part size	member size	diameter	Ink guiding	ratio		flow
	a/b/c (mm)	d/e/f (mm)	W (mm)	part system	(%)	Visibility	amount
Example 1	5.1/5.9/2.5	6.5/8.0/6.0	φ0.7	free ink	67	◯	◯
Example 2	5.1/5.9/2.5	6.5/8.0/6.0	φ2.3	free ink	48	◯	◯
Example 3	5.1/5.9/2.5	5.0/6.5/6.0	φ0.15	free ink	75	◯	◯
Example 4	5.1/5.9/4.0	5.1/6.5/6.0	φ1.4	free ink	42	◯	◯
Comparative	5.1/5.9/4.0	5.0/6.5/6.0	φ1.8	free ink	37	Δ	◯
Example 1
Comparative	5.1/5.9/2.5	6.5/8.0/6.0	φ0.08	free ink	74	◯	X
Example 2
Comparative	5.1/5.9/2.5	6.5/8.0/6.0	φ1.4	porous	59	◯	X
Example 3				member
Comparative	5.1/5.9/2.5	6.5/8.0/6.0	φ3.2	free ink	22	◯	X
Example 4
Comparative	Japanese patent application Laid-Open	free ink	34	X	◯
Example 5	No. 69426/2007, FIG. 1 (FIG. 28 in the
	present application)
Comparative	Japanese patent application Laid-Open	free ink	35	X	◯
Example 6	No. 69427/2007, FIG. 1 (FIG. 29 in the
	present application)

As apparent from the results of Table 1 described above, it has become clear that in Examples 1 to 4 falling in the scope of the present invention, provided are writing instruments which can be endowed with a sufficiently high visibility making it possible to read characters written toward a writing direction more surely than ever and which can be used to end of writing as compared with writing instruments in Comparative Examples 1 to 6 falling outside the scope of the present invention.

In Comparative Examples 5 and 6 (Japanese Patent Application Laid-Open No. 69426/2007, FIG. 28 in the present application, Japanese Patent Application Laid-Open No. 69427/2007, FIG. 29 in the present application), a writing direction can be visually recognized via a free ink guiding part, but it is hard to be visually recognized in ordinary use such as writing, and the satisfactory visibility can not be endowed.

Test Example 2

Examples 5 to 7 and Comparative Examples 7 to 8

In Test Example 2, the writing part porous member and the holding member were adhered by changing an adhered face form, adhered face dimensions and an adhered face shortest length to evaluate an adhesive strength and a sealing performance by the following evaluation methods. The evaluation results thereof are shown in the following Table 2.

A writing instrument equipped with the pen tip used in Example 1 described above and produced by the following method was used. The writing part porous member was adhered to the holding member by the following method.

The relay porous member and the writing part porous member were adhered by impregnating them with an organic solvent in a state in which the respective porous members were temporarily inserted into the holding member and then drying them.

Evaluation Method of Adhesive Strength:

The writing part porous member adhered was peeled off with a hand covered with a rubber glove and evaluated according to the following evaluation criteria.

Evaluation Criteria of Adhesive Strength:

◯: satisfactory adhesive strength, and when the writing part porous member is tried to be peeled off, the writing part porous member is broken before the adhered part is peeled off.

Δ: adhesive strength of a level in which it stands ordinary use; short of an adhesive strength; when the writing part porous member is tried to be peeled off, the writing part porous member itself is peeled off; and it is not peeled off in writing.

x: short of an adhesive strength, and the writing part porous member is peeled off from the holding member in writing.

Evaluation Method of Sealing Performance:

The sealing performance was evaluated by whether or not sealing was broken in writing and whether or not sealing was broken in allowing the writing instrument to freely fall from a height of 150 cm onto a concrete floor with the pen tip turned upward according to the following evaluation criteria. When sealing is broken, air (air bubbles) gets into a free ink guiding part, and therefore it can be visually confirmed.

Evaluation Criteria of Sealing Performance:

◯: no problem on sealing performance.

Δ: sealing is broken by drop impact and the like, and fine air bubbles get into the ink guiding part.

x: sealing is broken by drop impact and the like, and large air bubbles get into the ink guiding part.

TABLE 2
				Adhered
	Adhered		Ink	face
	face	Adhered face	guiding	Shortest	Adhesive	Sealing
	form	dimension	part	length	strength	performance
Example 5	rectangle	3 mm × 6	mm	diameter: 1 mm	1 mm	◯	◯
Example 6	circle	diameter: 6	mm	diameter: 1 mm	2.5 mm	◯	◯
Example 7	bent face	bottom: 1.6 × 6	mm	diameter: 1 mm	1.3 mm	◯	◯
		side face: 1 × 6	mm
Comparative	rectangle	1.6 mm × 6	mm	diameter: 1 mm	0.3 mm	Δ	X
Example 7
Comparative	circle	diameter: 1.6	mm	diameter: 1 mm	0.3 mm	Δ	X
Example 8

As apparent from the results of Table 2 described above, it has become clear that in Examples 5 to 7 falling in the scope of the present invention, the writing instruments are excellent in an adhesive strength and a sealing performance as compared with the writing instruments in Comparative Examples 7 to 8 falling outside the scope of the present invention.

Test Example 3

Examples 8 to 10 and Comparative Examples 9 to 10

In Test Example 3, the adhesive strength and the sealing performance depending on the thickness of the holding member resin layer were evaluated by the evaluation methods described above. The evaluation results thereof are shown in the following Table 3.

Used was a writing instrument equipped with the pen tip used in Example 1 described above and produced by using the same method as in Test Example 2 described above, except that only a thickness of the holding member resin layer was changed.

	TABLE 3
	Thickness of the
	holding member	Adhesive	Sealing
	resin layer	strength	performance	Remarks
Example 8	10 μm	◯	◯	—
Example 9	100 μm	◯	◯	—
Example 10	800 μm	◯	◯	—
Comparative	less than 1 μm	X	X	not adhered
Example 9
Comparative	1500 μm	◯	Out of	ink guiding
Example 10			standard	part clogged

As apparent from the results of Table 3 described above, it has become clear that in Examples 8 to 10 falling in the scope of the present invention, the writing instruments are excellent in an adhesive strength and a sealing performance as compared with the writing instruments in Comparative Examples 9 to 10 falling outside the scope of the present invention. When a thickness of the holding member resin layer was less than 1 μm, the holding member resin layer could not be confirmed and stayed in a state in which it could not be adhered. In the writing instrument of Comparative Example 9 in which a thickness of the holding member resin layer was 1500 μm, the ink guiding part was clogged, and the ink flow amount was reduced very much.

Example 11

A writing instrument equipped with a pen tip having the following constitution and based on FIG. 8 to FIG. 21 and the ink having the composition described above were used. A pen feed as a writing part constituting the pen tip, a holding member, an ink guiding part and the like each having sizes shown below were used.

Constitution of Pen Tip:

Writing part pen tip: PE-made sintered feed, porosity: 60%, upper side length: 5 mm, lower side length: 6 mm, height: 3 mm, both sides of front end face 48 subjected to chamfering treatment

Holding member (including a main body part): acryl resin-made, visible light transmittance: 85% (reflectance was measured by means of a multi-illuminant colorimeter (MSC-5N), manufactured by Suga Test Instruments Co., Ltd. to determine a visible light transmittance).

An area (area ratio) of the visible part in the pen tip was calculated by measuring an actual dimension of the molded article to find that an area (area ratio) thereof was 90%.

Length X: 11 mm, a thickness: 3.2 mm and a lateral direction length: 6.8 mm.

Ink guiding part: cylindrical form, diameter W: 0.7 mm, length: 7.1 mm, a visible light transmittance in a state in which the ink was contained therein: 27%

Constitution of Writing Instrument Members Other than the Pen Tip:

Relay feed: PET fiber bundle, porosity: 65%, φ3×24 mm

Gap part Y: 1 mm, size and the like of convex part 49a: φ2×1 mm

Ink occulusion body: PET fiber bundle, porosity: 85%, φ13×55 mm

Writing instrument main body and cap: polypropylene (PP)-made

The pen feed was adhered to the holding member in the following manner.

As described in detail in the embodiment, the pen feed was adhered by impregnating it with an organic solvent (ethyl acetate) in a state in which the pen feed was mounted in the holding member from a chamfered part side and then drying it.

Example 12

Used was a writing instrument in which only the pen tip shown in FIG. 13 was changed to that shown in FIG. 22 in the writing instrument used in Example 11 described above, to be specific, a writing instrument equipped with the pen tip provided with the gap part 49 having no convex part 49a. The respective dimensions of the pen feed, the relay feed and the ink occulusion body are the same as those in Examples 11 described above, and the same ink was used.

Reference Example

Used was a writing instrument in which only the pen tip shown in FIG. 13 was changed to that shown in FIG. 24 in the writing instrument used in Example 11 described above, to be specific, a writing instrument equipped with the pen tip which did not have the gap part 49 and the convex part 49a and in which an end face of the relay feed was brought into contact with an end face of the ink guiding part. The respective dimensions of the pen feed, the relay feed and the ink occulusion body are the same as those in Examples 1 and 2 described above, and the same ink was used.

The respective writing instruments obtained in Example 11, Example 12 and Reference Example each described above were used to evaluate an ink flow amount by the following evaluation method.

Evaluation Method of Ink Flow Amount:

The respective writing instruments were set in an automatic writing equipment to write a straight line on a wood free paper face at a writing angle of 65°, a writing force of 1 N and a speed of 7 cm/s in a distance of 100 m according to JIS 56037, and then a state of the written line was visually confirmed to evaluate the ink flow amount according to the following evaluation criteria. In the present evaluation method, the writing distance was changed from 20 m to 100 m as compared with the evaluation method of the ink flow amount in Examples 1 to 4 described above.

Evaluation Criteria of Ink Flow Amount:

⊚: good writing property and no blurring in the drawn lines up to 100 m.

Δ: unsatisfactory writing property and blurring in the drawn lines.

x: unsatisfactory writing property and marked blurring in the drawn lines.

In the evaluation of the ink flow amounts in the respective writing instruments used in Examples 11 and 12 and Reference Example each described above, given were “⊚” to Example 11, “⊚” to Example 12 and “Δ to x” to Reference Example.

Accordingly, in the writing instrument of Example 11 (FIG. 13) in which the gap part and the convex part were formed between the step part and the relay feed in the pen tip and the writing instrument of Example 12 (FIG. 22) in which the gap part was formed, an ink from the ink occulusion body 20 could be fed continuously and efficiently to the relay feed, the gap part (and the convex part), the ink guiding part and the pen feed by a capillary action, and therefore it was found that obtained was a writing instrument in which a suitable ink flow amount was secured to prevent blurring in writing and make it possible to contribute to stabilization of a writing flow amount.

In contrast with this, it was found that in the writing instrument of Reference Example (FIG. 24) in which an end face of the relay feed is brought into contact with an end face of the ink guiding part, blurring in writing was observed in the evaluation of the ink flow amount up to a distance of 100 m and that the writing instrument was inferior in stabilization of a writing flow amount.

In the writing instruments of Examples 11 and 12 described above, a chamfered part was formed in an end face of the pen feed 45 in holding the ink guiding part 50 and the pen feed 45, and the contact part 58 for holding the pen feed 45 in the holding member 55 was formed. Accordingly, the pen feed 45 was readily set up into the holding member 55, and a mounting position of the pen feed 45 could be stabilized.

Also, the writing instruments obtained in Examples 11 and 12 were used to write on characters, and an extent of seeing an opposite side via the visible part in writing was visually confirmed to find that a visible part area (area ratio) of the pen tip was 90%. Accordingly, the writing instruments had a satisfactory visibility to make seeing very easy and could write while reading characters written toward a writing direction.

Further, the writing instruments of Examples 11 and 12 were used to evaluate whether or not sealing was broken in allowing the writing instrument to freely fall from a height of 150 cm onto a concrete floor with the pen tip turned upward to find that air did not get into the ink guiding part by drop impact and that the writing instruments had a good writing performance and caused no problems on a sealing performance.

INDUSTRIAL APPLICABILITY

The writing instruments of the present invention can suitably be used for writing instruments of types called an underline pen, a paint marker, an oil-based marker and an aqueous marker.

LETTERS AND NUMERALS

• A Writing instrument
• 10 Barrel
• 11 Rear barrel
• 15 Front holder
• 20 Ink occulusion body
• 30 Relay porous member
• 40 Pen tip
• 45 Porous member (pen feed) as writing part
• 49 Gap part
• 50 Ink guiding part
• 55 Holding member
• 60 Cap member

Claims

1. A writing instrument comprising a pen tip equipped with a porous member as a writing part and a holding member holding the above porous member and having at least one ink guiding part for feeding an ink to the writing part, and further comprising a relay porous member for feeding an ink contained in a writing instrument main body to the ink guiding part provided in a central part of a longitudinal direction of the holding member and in which the holding member is a visible part enabling to visually recognize a writing direction, wherein an area ratio of the above visible part is 40% or more of the pen tip protruding from a tip part of the writing instrument main body, and an area ratio of the visible part on a side face of the holding member in the pen tip is 40% or more.

2. The writing instrument as described in claim 1, wherein a cross-sectional area of the ink guiding part is less than a cross-sectional area of a holding member side in the writing part.

3. The writing instrument as described in claim 1, wherein a taper is formed toward a writing part side in the ink guiding part.

4. The writing instrument as described in claim 1, wherein the ink is fed directly to the ink guiding part.

5. The writing instrument as described in claim 1, wherein the writing part is inclined toward a major axis direction of a main body axis.

6. The writing instrument as described in claim 1, wherein faces forming the visible part of the holding part are almost parallel.

7. The writing instrument as described in claim 1, wherein a resin constituting the holding member gets into irregularities of porous member pores from the holding member in a part in which the porous member as the writing part is brought into contact with the holding member to form a holding member resin layer, whereby the porous member and the holding member are fixed adhered to each other.

8. The writing instrument as described in claim 1, wherein a holding member resin layer is formed in an end face of the ink guiding part at a side of the porous member as the writing part in an interface between the porous member and the holding member, and the holding member resin layer in the above interface is formed toward a whole direction of the end face.

9. The writing instrument as described in claim 1, wherein a main body part having a cylindrical part for holding the relay porous member is connected with the holding member; a step part with which the relay porous member can be brought into contact is formed in the cylindrical part; and a gap part is formed between the step part and the relay porous member.

10. The writing instrument as described in claim 1, wherein a chamfered part is formed in an end face at a side of the porous member, while a contact part for holding the porous member is formed in the holding member.