JP3474876B2 - writing implements - Google Patents

Description

Detailed Description of the Invention

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a writing instrument that has a pen tip on both sides of a barrel, which serves as the writing part, and supplies ink impregnated in an ink reservoir inside the barrel to the pen tip. More specifically, the present invention relates to a writing instrument with this structure that allows easy detection of the ink end sign.

[0002]

2. Description of the Related Art Conventionally, writing instruments that allow you to know the remaining amount of ink or when the ink is running out include, for example, direct-liquid writing instruments with a collector structure in which liquid ink is stored directly inside the barrel, writing instruments in which ink is stored in a cartridge-type ink reservoir, and ballpoint pens in which ballpoint pen ink is filled in a transparent refill.

However, in the case of writing instruments that supply ink for writing instruments, such as water-based ink or oil-based ink, which is impregnated in an ink reservoir inside a barrel, to the pen tip that serves as the writing part, that is, so-called cotton-filled writing instruments, there are currently no writing instruments equipped with a mechanism that can detect the ink end sign.
With a writing instrument of this structure, you can only tell that the ink is finished when you use it until the ink starts to fade while writing, and then you can either discard it or refill it and reuse it. However, fading can also occur when the nib of the pen smudges, so if the nib smudges due to drying out even though there is still enough ink impregnated in the ink reservoir, this is not a sign that the ink is actually finished, and there is an issue with usability, etc.

On the other hand, Japanese Patent Application Laid-Open No. 6-270585 discloses a writing instrument in which a spool that serves as an ink storage body is housed in a transparent barrel, the ink impregnated in the spool is supplied to the pen tip that serves as the writing part, and the contents of the writing instrument from the spool to the pen tip can be seen. However, with a writing instrument of this structure, although it is possible to check to some extent the amount of ink remaining by the degree of ink color stored when the amount of ink stored in the spool becomes low, it is not possible to reliably detect the end of the ink, and even with this writing instrument, there are problems with usability, etc.

[0005]

[Problem to be Solved by the Invention] The present invention has been made in consideration of the above-mentioned problems and current state of the prior art, and aims to solve them. It is an object of the present invention to provide a writing instrument that supplies writing instrument ink, such as water-based ink or oil-based ink, impregnated in an ink absorbing body inside the barrel to the pen tip, which serves as the writing part, and that can easily and reliably detect the end of ink, and a further object of the present invention is to provide a writing instrument that can also improve the ink consumption rate in the ink absorbing body.

[0006]

[Means for solving the problem] After extensive research into the problems of the above-mentioned prior art, the inventors discovered that a writing instrument that satisfies the above-mentioned objectives can be obtained by configuring the barrel of a writing instrument that supplies ink impregnated in the ink reservoir inside the barrel to the pen tip, which is the writing part, in a specific manner, and by configuring the mechanism that supplies ink from the ink reservoir to the pen tip in a specific manner, and thus completed the present invention.

That is, the writing implement of the present invention comprises the following (1) to (3):
(18) (1) A writing instrument that supplies ink impregnated in an ink occlusion body in a barrel to a nib that serves as a writing part, wherein the ink impregnated in the ink occlusion body is supplied to a visible ink guide tube via a relay core and to the nib via the ink guide tube, and an ink-out sign from the ink occlusion body is detected by visually checking the ink guide tube through a visual check part formed on the barrel. (2) A twin-type writing instrument that supplies ink impregnated in an ink occlusion body in a barrel to each nib that serves as a writing part provided on both sides of the barrel, wherein the ink supplied to either nib is supplied to a visible ink guide tube via a relay core and to the nib via the ink guide tube, and an ink-out sign from the ink occlusion body is detected by visually checking the ink guide tube through a visual check part formed on the barrel. (3) The ink cartridge (1) characterized in that the relay core is in contact with the inside of the ink occluder over a length of 5% or more of the total length of the ink occluder.
(4) The cross-sectional area of the intermediate core is 1 to 9 times the cross-sectional area of the ink occlusion body.
(5) A writing instrument according to any one of (1) to (3) above, characterized in that the capillary force of the intermediate tip is greater than that of the ink occlusion body. (6) A writing instrument according to any one of (1) to (5) above, characterized in that the cross-sectional structure of the intermediate tip has an inner layer portion and an outer layer portion, and the capillary force of the outer layer portion is greater than that of the inner layer portion. (7) A writing instrument according to any one of (1) to (6) above, characterized in that the ink supplied to the visible ink guide tube by the intermediate tip is further supplied to the pen tip via the pen tip intermediate tip. (8) A writing instrument according to any one of (1) to (7) above, characterized in that the surface tension of the surface of the visible ink guide tube that comes into contact with the ink or the material of the ink guide tube itself is smaller than the surface tension of the ink. (9) A writing instrument as set forth in any one of (1) to (8) above, characterized in that the distribution of capillary force in the ink occlusion body becomes greater toward the pen tip side. (10) A writing instrument as set forth in any one of (1) to (9) above, characterized in that the inner diameter of the barrel becomes narrower toward the pen tip side. (11) A writing instrument as set forth in any one of (1) to (10) above, characterized in that a plurality of ribs are formed in the axial direction on the inside of the barrel on the pen tip side. (12) A writing instrument as set forth in any one of (1) to (11) above, wherein the intermediate core is one of a fiber bundle core, a porous resin particle body, and a sliver core, and these intermediate cores have continuous flow paths, thereby making it possible to control the cross-sectional area of the ink flow path in the ink guide tube while maintaining the apparent cross-sectional area of the ink guide tube. (13) A writing instrument as set forth in any one of (1) to (12) above, in which the ink guide tube, having ink visibility, is filled with a fiber bundle or a porous resin particle body having a lower surface tension than the ink and a different color from the ink, thereby making it possible to substantially control the ink flow path cross-sectional area and the ink flow resistance while maintaining the apparent cross-sectional area of the ink guide tube. (14) A writing instrument as set forth in any one of (1) to (13) above, characterized in that a plurality of ink guide tubes are formed. (15) A writing instrument as set forth in any one of (1) to (14) above, characterized in that the length of the visible portion of the barrel is 1 mm or more and less than the entire length of the writing instrument. (16) A writing instrument in which the ink flow path cross-sectional area of the ink guide tube is 8 × 10 ^-2 to
(17) A writing instrument according to any one of ( ¹ ) to (16) above, characterized in that the ink has a surface tension of 18 mN/m or more at 25°C. (18) A writing instrument according to any one of (1) to (16) above, characterized in that the ink has a viscosity coefficient of 500 mPa·s at 25°C.
A writing instrument according to any one of (1) to (17) above, characterized in that:

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
A writing instrument that supplies ink impregnated in an ink absorbing body within a barrel to a pen tip that serves as the writing part, characterized in that the ink impregnated in the ink absorbing body is supplied to a visible ink guide tube via an intermediate core and is supplied to the pen tip via the ink guide tube, and the ink-out sign from the ink absorbing body is detected by visually checking the ink guide tube through a visual check section formed on the barrel; and a twin-type writing instrument that supplies ink impregnated in an ink absorbing body within a barrel to each pen tip that serves as a writing part provided on both sides of the barrel, characterized in that the ink supplied to one of the pen tips is supplied to a visible ink guide tube via an intermediate core and is supplied to the pen tip via the ink guide tube, and the ink-out sign from the ink absorbing body is detected by visually checking the ink guide tube through a visual check section formed on the barrel.

1 to 3 show a first embodiment of the present invention, which can be suitably applied to a felt-tip pen, a marker, a whiteboard marker, etc. As shown in FIGS. 1 and 3, the writing implement A of this first embodiment comprises a barrel 10 which is the main body of the writing implement, an ink occlusion body 2,
The pen includes a small diameter portion 10a having a tapered tip end, a relay core 25, an ink guide tube 30, a pen tip 40, and a tail plug 50. The barrel 10 is made of, for example, synthetic resin, and is formed by integrating a small diameter portion 10a having a tapered tip end and a large diameter portion 10b. The small diameter portion 10a has a fitting portion 11 into which the pen tip 20 is fitted, and the large diameter portion 10b is configured to accommodate an ink occlusion body 20 impregnated with writing instrument ink, the relay core 25, and the ink guide tube 30.

[0010] Furthermore, as shown in Figures 1 and 3, the tip side of the large diameter portion 10b of the barrel 10 has a visible portion 12 made of a transparent or semi-transparent material so that the inside of the barrel can be seen, and the rest of the barrel is a non-visible portion made of a separate material, etc.
The entire barrel 10 may be made of a transparent or translucent material that allows visibility, and the entire barrel 10 may be made of a transparent or translucent material that allows visibility, with the area other than the visible portion 12 being a non-visible area, such as a colored or decorative portion. The overall length of the visible portion 12 need only be such that the ink guide tube 30 held within the barrel 10 can be seen from the visible portion 12, and is preferably 1 mm or more but less than the overall length of the writing instrument body (the barrel in this embodiment), and preferably 5 mm or more. If the overall length of the visible portion 12 is less than 1 mm, it will be difficult to see the ink end signal, and the detection function will not be achieved.

The ink occlusion body 20 is impregnated with ink for writing instruments, such as water-based ink or oil-based ink, and may be made of, for example, natural fibers, animal hair fibers, polyacetal resins, acrylic resins, polyester resins, polyamide resins,
The material includes fiber bundles made of one or a combination of two or more types of resins such as polyurethane resin, polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, polyphenylene resin, etc., processed fiber bundles such as felt, and porous bodies such as sponge, resin particles, and sintered bodies, and is housed within the barrel 20 by a rear retaining body 21 that seals the front part of the barrel 10 and a tail plug 50.

The relay core 25 is a fiber bundle core made of fiber bundles, felt, etc., similar to the ink occlusion body 20.
Alternatively, the ink guide tube 30 may be made of a porous resin particle material such as a hard sponge or a sintered resin particle material, or a sliver core having continuous pores (flow paths), and the ink impregnated in the ink occlusion body 20 may be visible through the relay core 20.
The shape, structure, etc. of the material are not particularly limited as long as it can be supplied to the
As shown in FIG. 1, the tip of the relay core 25 has an insertion portion 26 that is inserted into the rear end portion 30a of the ink guide tube 30.
The ink occlusion body 20 has an acute angled portion 27 at its rear end.
The relay core 25 has an insertion portion 26 and an acute angle portion 27, and the hollow portion 20a is provided so as to be in contact with the outer layer of the relay core 25.
Due to the structure of the ink occlusion body 20 having the diameter 0a, the ink impregnated in the ink occlusion body 20 can be more efficiently supplied to the visible ink guide tube 30 via the relay core 25. Furthermore, the capillary force of the relay core 25 is made larger than the capillary force of the ink occlusion body 20, and
The cross-sectional structure of the relay core 25 has an inner layer portion and an outer layer portion, and the capillary force of the outer layer portion is made greater than the capillary force of the inner layer portion. For example, the fiber bundle density of the outer layer portion is made fine and the fiber bundle density of the inner layer portion is made coarse, so that the ink impregnated in the ink occlusion body 20 is guided through the ink guide tube 30.
This will enable efficient supply to

Here, the relay core 25 is 5% or more of the total length (L) of the ink occluding body 20, preferably 10% or more and 100% or more.
% or less of the total length L of the ink occlusion body 20, that is, the length _L1 of the relay core 25 that contacts the inside of the ink occlusion body 20 is desirably 5% or more, preferably 10% or more, more preferably 20% or more and 100% or less, and particularly preferably 50% or more and 100% or less of the total length L of the ink occlusion body 20. This makes it possible to further efficiently supply the ink contained in the ink occlusion body 20 to the ink guide tube 30.
The length _L1 of the relay core 25 shown in FIGS. 1(a) and 1(b) is
It is set to 20% of the total length L of the ink occlusion body 20.
If the length of contact with the inside of the ink occlusion body 20 is less than 5 _% , the ink consumption rate may be at the same level as that of a normal cotton-filled writing implement.
%, preferably 5 to 50%, more preferably 10 to
If the cross-sectional area _W1 of the relay core 25 is less than 1%, depending on the shape of the pen tip 40, the amount of ink supplied from the ink occlusion body 20 may be insufficient, causing problems such as blurred lines and poor fast writing response.
If it exceeds 90%, not only will it be difficult to insert into the ink occlusion body 20, but the function of the ink occlusion body 20 will be reduced, and the writing implement will be no different from a conventional batting-type writing implement having a relay core 25 _.
By setting the cross-sectional area W of the ink occlusion body 20 to 1 to 90%, the ink contained in the ink occlusion body 20 can be more efficiently supplied to the ink guide tube 30.
The cross-sectional area W ₁ is 60% of the cross-sectional area W of the ink occlusion body 20.
is set to.

As shown in FIGS. 1(a) and 1(b), the ink guide tube 30 is a visible cylindrical (tubular) ink flow path member, and is made of, for example, resin, rubber,
Alternatively, the ink guide tube 30 may be made of a transparent or translucent material such as glass. Specifically, examples of transparent or translucent resins include polyolefin resins such as polypropylene, polyethylene, cyclic polyolefin, and poly(1-methyl-4-pentene), polycarbonate, polystyrene, polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, as well as fluoroplastics such as fluororesins and vinylidene fluoride. Examples of transparent or translucent rubber include fluororubber and silicone rubber. In this embodiment, the ink guide tube 30 is made of polypropylene. Furthermore, at least the wall surface of the resin, rubber, or transparent or translucent material such as glass that comes into contact with the ink may be subjected to a surface treatment that reduces the surface energy below that of the ink. Specifically, examples of such treatments include a fluorine coating, a fluororesin coating, or a silicone resin coating with a dimethyl silicone skeleton. The rear end portion 30a of the ink guide tube 30 penetrates the rear holder 21 and is connected to the ink occlusion body 2.
The ink guide tube 30 is connected to the inside of the barrel 10, and the front end portion 30b passes through the front holder 22 that seals the inside of the small diameter portion 10a of the barrel 10 and is fitted into the rear end portion of the pen tip 40.
and the front holding body 22, a visible space portion 1 is formed in the barrel 10.
3 is formed and is held in the center of the visible space portion 13.

With this configuration, the visible portion 12 of the barrel 10
If the ink guide tube 30 is visually recognized, it can be easily seen through the visual recognition portion 12.
In addition, the ink contained in the ink occlusion body 20 is
The ink is efficiently guided through the relay core 25.
The ink flows into the conduit 30 and reaches the pen tip through the ink guide tube 30.
The ink is supplied to the ink guide tube 30.
The overall length is set appropriately depending on the type of pen tip 40.
The total length of the ink guide tube is usually the same as that of the ink occlusion body 20.
The ink is drawn from the front end of the ink occlusion body 20 to the pen tip 40 by capillary force.
The length is specified within the range of that length.
The ink flow path cross-sectional area of the ink guide pipe 30 is
The ink flows more smoothly through the ink guide tube 30.
To pass through, 8 x 10^-2~80mm ², more preferably
Usually 0.5 to 20 mm²It is desirable to do this.
Ink flow path cross-sectional area is 8 x 10^-2mm²If it is less than
The ink flow rate is low, which results in poor ink tracking when writing.
On the other hand, 80 mm²When the ink flow rate exceeds
The length cannot be made long, making it difficult to visually detect when the ink has run out.
In addition, 80 mm²The length of the ink guide tube with a cross-sectional area exceeding
If the time is longer, it becomes easier to visually detect when the ink has run out.
In this case, when writing with the pen pointing downward,
An excessive amount of ink will flow out.

[0016] Furthermore, in order to supply ink from the ink occlusion body 20 to the pen tip 40 more smoothly and easily, it is preferable that the surface tension of the surface of the visible ink guide tube 30 that comes into contact with the ink or the material of the ink guide tube 30 itself be smaller than the surface tension of the ink. If the surface tension of the ink guide tube 30 that comes into contact with the ink is greater than the surface tension of the ink, the surface of the ink guide tube 30 that comes into contact with the ink can be made smaller than the surface tension of the ink by subjecting it to fluorine treatment, silicone treatment, or the like. Furthermore, the cross-sectional shape of the ink guide tube 30 can be, for example, a circular shape (Fig. 2(a)), a triangular shape (Fig. 2(b)), or a rectangular shape (Fig. 2(c)), as shown in Figures 2(a) to 2(i)
Square shape (Fig. 2(c)), pentagonal shape (Fig. 2(d)),
Examples of shapes include polygonal shapes such as a hexagonal shape (Fig. 2(e)), a diamond shape (Fig. 2(g)), an elliptical shape (Fig. 2(f)), and a star shape (Fig. 2(h)), and are not particularly limited as long as they allow smooth supply of ink from the ink occlusion body 20 to the pen tip 40 and do not impede visibility. The ink guide tube 30 of this embodiment has a circular cross-sectional shape.

The pen tip 40 may be made of, for example, natural fiber, animal hair fiber, polyacetal resin, acrylic resin, polyester resin, polyamide resin, polyurethane resin,
The pen tip is made of a parallel fiber bundle made of one or a combination of two or more types of resins such as polyolefin resin, polyvinyl resin, polycarbonate resin, polyether resin, polyphenylene resin, etc., a fiber core made by processing a fiber bundle such as felt or processing such a fiber bundle with resin, or a porous body made by fusing various types of plastic powder, etc., and the shape of the pen tip is selected according to the type of writing instrument, for example, a marking pen, a felt-tip pen, etc.

The ink to be impregnated into the ink occlusion body 20 may be any ink for writing instruments, such as water-based ink or oil-based ink, having a commonly used composition.
There are no particular limitations, and examples include water-based or oil-based liquid inks suitable for use in felt-tip pens, marking pens, ballpoint pens, whiteboards, etc. Preferably, in order to better detect the end sign in the ink guide tube 30, the surface tension of the ink is 18 mN/m or more at 25°C.
More preferably, it is desirable to set it to 20 to 50 mN/m. The surface tension of the ink can be adjusted by blending a surfactant or the like into the ink composition as needed. Furthermore, in order to more smoothly and smoothly supply ink from the ink occlusion body 20 to the pen tip 40 via the relay core 25 and the ink guide tube 30, it is preferable to set the viscosity coefficient of the ink to 500 at 25°C.
It is desirable that the viscosity coefficient of the ink be no more than 500 mPa·s, more preferably no more than 200 mPa·s, and particularly preferably 1 to 100 mPa·s. If the viscosity coefficient of the ink exceeds 500 mPa·s, the fluidity of the ink will be poor and a sufficient amount of ink will not flow out, which may result in blurred lines or the inability to write quickly due to insufficient flow rate. The viscosity coefficient of the ink can be adjusted by adding a thickener or the like to the ink composition as needed.

In the writing implement A of the first embodiment thus constructed, as shown in Figures 1 and 3, the ink impregnated in the ink occlusion body 20 passes through the ink guide tube 30 via the intermediate core 25 and penetrates into the pen tip 40, enabling writing. In the present invention, the ink impregnated in the ink occlusion body 20 is not introduced directly into the ink guide tube 30 by capillary force, but is introduced into the ink guide tube 30 via the intermediate core 25, so that the ink impregnated in the ink occlusion body 20 can be efficiently and smoothly introduced into the ink guide tube 30.
In the writing instrument A of the first embodiment, the ink impregnated in the ink occlusion body 20 passes through the ink guide tube 30 via the relay core 25 and is introduced into the pen tip 4.
0, when the ink impregnated in the ink occlusion body 20 decreases due to writing and runs out, it can be determined by the fact that ink no longer passes through the ink guide tube 30. That is, with the writing instrument A of this embodiment, the ink end sign from the ink occlusion body 20 can be detected by visually checking the ink guide tube 30 through the visual checking portion 12 formed on the barrel 10. Therefore, it can be clearly and easily determined visually whether the ink smearing at the pen tip 40 is due to drying at the pen tip 40 or is due to the actual end of the ink due to consumption.

In this embodiment, the tail plug 50 is attached to the barrel 1.
The tail plug 50 is fixed to the rear end of the barrel 10, but the tail plug 50 is detachably attached to the rear end of the barrel 10, and after the end of the ink is detected by visual confirmation of the ink guide tube 30, the tail plug 5
The ink guide pipe 30 may be removed and refilled with replenisher ink.
The ink is supplied to the pen tip 40 excessively from the
In order to prevent ink from leaking from the small diameter portion 10a, an ink absorber may be provided on the outer periphery of the rear end portion of the pen tip 40. This ink absorber is provided around the pen tip 40 in the small diameter portion 10a.
Furthermore, the end face of the ink occluder 20 on the side where the relay core 25 inserted into the rear end portion of the ink guide tube 30 and the ink occluder 20 are joined is closed to the outside air, so in this embodiment, the end face of the ink occluder 20 on the side where the relay core 25 inserted into the rear end portion of the ink guide tube 30 and the ink occluder 20 are joined is in contact with the front holder 22 and the tail plug 5.
0, the writing implement A is closed to the outside air, so that no outside air can flow in, and it is possible to prevent air from flowing into the ink guide tube 30. Furthermore, in the writing implement A of the first embodiment, the relay core 25 is made of one of a fiber bundle core, a porous resin particle body, and a sliver core, and these relay cores 25 have a continuous flow path, so that the ink guide tube 30 is substantially expanded while maintaining the apparent cross-sectional area of the ink guide tube.
This allows the cross-sectional area of the ink flow path to be controlled. In other words, by controlling the cross-sectional area of the ink flow path, when the writing implement is dropped or otherwise subjected to an impact, the ink in the ink guide tube 30 becomes less likely to move due to pipe resistance, making it possible to suppress ink dripping from the pen tip 40 side. Furthermore, by controlling the cross-sectional area of the ink flow path, it is possible to suppress the amount of ink flowing out after the end is detected, and to prevent poor writing due to excessive ink flow.

4(a) to 4(c) show modified examples of the first embodiment. Fig. 4(a) shows a configuration in which the distribution of capillary force of the ink occlusion body is made larger toward the pen tip side, for example, a structure in which the gaps between the fiber bundles constituting the ink occlusion body 20 become narrower toward the pen tip side, i.e., a structure in which the gaps between the fiber bundles constituting the ink occlusion body 20 become narrower toward the pen tip side, i.e., a structure in which the gaps between the fiber bundles
The pore size is 20b and the dense portion 20c.
(b) shows a structure in which the inner diameter of the barrel 10 becomes narrower toward the pen tip side (tapered shape), and the ink occlusion body 2
The 0 also has a structure that narrows as it moves towards the pen tip.
The width (diameter) of the relay core 25 is set to be approximately the same as the inner diameter of the ink guide tube 30. In FIG. 4(c), ribs 15, 16 are provided on the inner wall of the barrel 10 that accommodates the ink occlusion body 20.
4(a) to 4(c) or a combination thereof is further adopted in the writing instrument A of the first embodiment.
The ink impregnated in the ink occlusion body 20 flows smoothly into the ink guide tube 30 via the relay core 25, and the ink reaches the pen tip 4.
0 will be supplied well.

5(a) and (b) show a second embodiment of the present invention. Writing implement B of this second embodiment
The ink supplied from the relay core 25 to the visible ink guide tube 30 is further supplied to the pen tip 4 via the pen tip relay core 28 inserted into the front end portion 30b of the ink guide tube 30.
5(a) and 5(b), the same components as those in the first embodiment are given the same reference numerals and their description will be omitted. In the writing instrument B of this second embodiment, as in the first embodiment, the ink impregnated in the ink occlusion body 20 passes through the ink guide tube 30 via the relay core 25 and is supplied to the pen tip 4 via the pen tip relay core 28.
0, writing becomes possible. In addition, with this writing instrument B, the ink end sign of the ink occlusion body 20 can be detected by visually checking the ink guide tube 30 through the visual checking portion 12 formed on the barrel 10. In the above embodiment, the pen tip relay core 28
However, the pen tip 40 and the pen tip relay core 28 may be integrated, that is, the rear end portion of the pen tip 40 may be the pen tip relay core 28. Furthermore, the writing instrument B of the second embodiment may be provided with a pen tip 40 and a pen tip relay core 28 as shown in FIG.
The modifications shown in (a) to (c) may also be applied (the same applies to the following embodiments).

6(a) and (b) show a third embodiment of the present invention. Writing implement C of this third embodiment
a plurality of visible ink guide tubes 31, 32;
In this embodiment, the ink guide tubes 31 and 32 are made of transparent or semi-transparent members of different lengths and have visibility.
The ink impregnated in the ink occlusion body 20 is supplied to the visible ink guide tubes 31 and 32 via the relay cores 25b and 25c having different lengths.
The width (diameter) of the relay cores 25b and 25c is
The only difference from the writing instrument A of the first embodiment is that the inner diameters of the pens 1 and 32 are approximately the same as those of the pens 1 and 32.
In (a) and (b), the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. In the writing instrument C of the third embodiment, the long ink guide tube 31 and the short ink guide tube 32 are as shown in FIG.
Both rear end portions 31a, 32a pass through the rear retaining body 21 and are fitted into the ink occlusion body 20 with a difference in length _X1 , and the front end portions 31b, 32b pass through the front retaining body 22 that seals the small diameter portion 10a of the barrel 10 and are fitted into the rear end portion of the pen tip 40 with their ends aligned.
As a result, the ink guide tubes 31 and 32 are held in the center of the visible space 13.

In the writing implement C of this third embodiment, as in the first embodiment, the ink impregnated in the ink occlusion body 20 passes through the ink guide tubes 31 and 32 via the intermediate cores 25b and 25c, respectively, and is supplied to the pen tip 40, enabling writing. Also, in this writing implement B, since the ends 31a and 32a of the ink guide tubes are inserted into the ink occlusion body 20 with a difference in length of _X1 , and the ends of the intermediate cores 25b and 25c are inserted into the ink occlusion body 20 with a difference in length of _X2 , when the ink impregnation rate of the ink occlusion body 20 is gradually consumed from its maximum by writing, the ink in the long ink guide tube 31 does not flow through the intermediate core 25b and is cut off, and the ink in the ink occlusion body 20
For example, when it is detected through the visual confirmation unit 12 that about 80% of the ink remains, and then ink is consumed by further writing, and the ink in the short ink guide tube 32 does not flow through the relay core 25c and runs out, that is, when the ink occluder 2
At time t0, it can be detected through the visual confirmation portion 12 that the ink has run out. Therefore, in the writing instrument C of the third embodiment, the ends 31a, 32a of the ink guide tube
By arranging the ends of the relay cores 25b and 25c with a difference in length of _X1 and the ends of the relay cores 25b and 25c with a difference in length of _X2 , the remaining amount of ink in the ink occlusion body 20 and the end sign can be detected by visually checking the ink guide tubes 31 and 32 through the visual checking section 12 formed on the barrel 10.

In the third embodiment, the ink guide tubes 31 and 32 are different in length. However, the ink guide tubes 31 and 32 are of the same length and the relay cores 25b and 25c are of the same length.
Even if the lengths of the ink guide tubes are different, the remaining ink amount and the end sign can be detected in the same manner as described above. In addition, in the second embodiment, the number of ink guide tubes is two, but depending on the application of the writing instrument, three or more ink guide tubes of different lengths or the same length may be provided as appropriate. Furthermore, in the writing instrument B of the second embodiment,
The modified examples shown in FIGS. 4A to 4C may also be applied (the same applies to the following embodiments).

7(a) to 7(c) show a fourth embodiment of the present invention. Writing implement D of this fourth embodiment differs from writing implement A of the first embodiment only in that the ink guide tube 35 is filled with a fiber bundle or porous resin particle body having a lower surface tension than the ink impregnated in the ink occlusion body 20 and a different color from the ink, such as a fiber bundle or porous resin particle body 36 (FIG. 7(b)) made of polyethylene tetrafluoride or the like, or a fiber bundle or porous resin particle body 37 (FIG. 7(c)) made of vinylidene fluoride or the like, thereby substantially controlling the cross-sectional area of the ink flow path through the ink guide tube and the flow resistance of the ink while maintaining the apparent cross-sectional area of the ink guide tube 35. The fiber bundle or porous resin particle body 36 or 37 (FIG. 7(c)) is filled with the fiber bundle or porous resin particle body 36 or 37 (FIG. 7(b)).
The length of the fiber bundle or porous resin particle body 36 or 37 of the fourth embodiment is shorter than the length of the ink guide tube 30 because the insertion portion of the relay core 25 is inserted into the rear end portion of the ink guide tube 35. In addition, in Figures 7(a) and (b), the same components as those of the first embodiment are given the same reference numerals and their description will be omitted. It is necessary to use the fiber bundle or porous resin particle body whose surface energy is lower than that of the ink, or to use one whose surface energy is lower than that of the ink by performing a surface treatment. The hue of the fiber bundle or porous resin particle body 36 or 37 of the fourth embodiment depends on the color of the ink occlusion body 2.
The color of the ink impregnated in the ink cartridge 0 is different from that of the ink impregnated in the ink cartridge 0, preferably
It is desirable that the color be one that can be hidden by the ink color used.
For example, if the ink is black, it will be white, if the ink is red, it will be blue, and if the ink is yellow, it will be black.
It may be transparent or translucent and does not necessarily have to be colored.

In the writing implement D of the fourth embodiment, the ink impregnated in the ink occlusion body 20 passes through the relay core 25d and the visible ink guide tube 35, in which a rod-shaped fiber bundle or porous resin particle body 36 or 37 is inserted without coming into contact with the inner wall of the ink guide tube 35, and is supplied to the pen tip 40, enabling writing. In this writing implement D, the fiber bundle or porous resin particle body 36 or 37, which has a lower surface tension than the ink and is a different color from the ink, is provided inside the ink guide tube 35 without coming into contact with the inner wall of the ink guide tube 35, thereby reducing the cross-sectional area of the ink flow path through the ink guide tube 35 and effectively reducing the cross-sectional area while keeping the apparent cross-sectional area of the ink guide tube the same, thereby reducing the volume of ink flowing through the ink guide tube 35, thereby simultaneously solving the problem of ink end detection and excessive ink outflow when ink ends. Furthermore, in the writing instrument D of the fourth embodiment, unlike the writing instruments of the first to third embodiments described above, in which the ink end sign is detected by visually checking whether the ink has run out in the ink guide tube,
When the ink runs out (ink runs out), the ink guide tube 35 is filled with a fiber bundle or a resin particle porous body 3 having a color different from the ink color.
Since the ink is visible in hues 6 or 37, the end of the ink can be more clearly visually indicated.

8 shows a fifth embodiment of the present invention. The writing implement E of this fifth embodiment has the following features: the pen tip 40 is for underlining, the tip barrel 41 that holds the pen tip is made of a separate member and is fixed to the tip of the barrel 10, the rear holder 21 and the front holder 22 are omitted, and
This writing instrument differs from the writing instrument A of the first embodiment in that a holding step portion 23 is provided around the circumference instead of the front holding body 22, and in that the shape and size of the relay core 25e are different. As with the writing instrument A, the ink supply and the ink end sign are displayed on the visual confirmation portion 12.
The ink guide tube 30 is visually detected through the sensor.

9 shows a sixth embodiment of the present invention. Writing instrument F of this sixth embodiment differs from writing instrument A of the first embodiment in that the pen tip 40 is for a ballpoint pen equipped with an ink guide core, the tip barrel 42 that holds the pen tip is made of a separate member and fixed to the tip of the barrel 10, the front holder 22 is omitted, and the shape and size of the relay core 25f are different. As with writing instrument A, the ink supply and ink end sign are detected by visually checking the ink guide tube 30 via the visual check section 12.

10 shows a seventh embodiment of the present invention, which is a twin-type writing implement G that supplies ink impregnated in an ink occlusion body 20 in a barrel 10 to an underlining pen tip 40 and a felt-tip pen tip 45, which are writing parts provided on both sides of the barrel 10. Ink is supplied from the ink occlusion body 20 to the pen tip 40 side in the same manner as in the fifth embodiment of FIG.
The ink is supplied smoothly and efficiently through the pen tip 45.
0 and contacts the ink reservoir 20, so that ink is directly supplied from the ink reservoir 20. Reference numeral 46 in the figure denotes a tip portion formed integrally with the barrel 10. In this twin-type writing instrument G, ink is consumed by each of the pen tips 40, 45, and as in the fifth embodiment,
The ink end sign of the ink occlusion body 20 is detected by visually checking the ink guide tube 30 through the visual checking section 12. Contrary to the above embodiment, the visual checking section 12, the ink guide tube 30, etc. are provided on the pen tip 40 side.
The visible portion 12, the ink guide tube 30, etc. may be provided on the side 5, and the rear end portion of the pen tip 40 may be fitted into the ink occlusion body 20 to make contact with it, thereby directly supplying ink from the ink occlusion body 20.

The writing implement of the present invention is not limited to the above-described embodiments, and can be modified in various ways without departing from the spirit of the present invention. For example,
The first embodiment (including the modified example of FIG. 4) to the seventh embodiment may be suitably combined, for example, the third embodiment.
Or the fourth embodiment may be replaced with the fifth embodiment, the sixth embodiment, or the seventh embodiment.
The present invention may be applied to the writing implements of the embodiments, and in each of the writing implements C to G of the third to seventh embodiments, a pen tip relay core may be added independently or integrally with the pen tip to efficiently supply ink in the ink guide tube 30 to the pen tip 40. In addition, the writing implement of the present invention is configured such that ink impregnated in the ink occlusion body 20 is supplied to the pen tip through the relay core 25 and the visible ink guide tube 30, and an ink end sign from the ink occlusion body 20 is displayed through the visible portion 12 formed on the barrel 10 by the ink guide tube 3.
Since the gist of the invention is a structure that allows the detection of zero by visually recognizing the zero, the configuration that does not deviate from this gist is not particularly limited, and various known writing instrument structures can be adopted, and the pen tip and ink type can be changed depending on the application, such as a ballpoint pen, a felt-tip pen, a marking pen, a brush pen, etc., so that the invention can be suitably applied to writing instruments for various uses. Furthermore, the invention can also be applied to applicators in which the writing instrument ink is used as correction fluid, coating fluid, liquid cosmetics, etc.

[0032]

EXAMPLES Next, the present invention will be described in more detail based on specific examples, but the present invention is not limited to the following examples. The surface tension of ink, etc. was measured by the Wilhelmy method (Kyowa Interface Science Co., Ltd., CBVP-Z model), and the viscosity coefficient of ink was measured with a rotational viscometer (Tokimec Co., Ltd., TV-20L).

[Example 1, Sign Pen] A sign pen conforming to Figures 1 and 3 was produced using the barrel, ink occluder, ink guide tube, relay core, pen tip, and ink composition described below. Barrel: Made of polypropylene, large diameter part 10 mm, visible part length 15 mm (parts other than the visible part are invisible due to a colored layer), total length 120 mm Ink occluder: Made of polyethylene terephthalate padding (porosity 80%), diameter 9 mm, length 60 mm Ink guide tube: Made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), inner diameter 3 mm, length 2
0 mm, ink flow path cross-sectional area approximately 7 mm ² , surface tension of the material of the ink guide tube itself (25°C) 20 mN/m, length of the rear end portion inserted into the ink occlusion body 20 3 mm Intermediate core Made of acrylic sliver (porosity 55%), diameter approximately 3 mm, length 20 mm, shape of insertion part: cylindrical, shape of acute angle part: conical Pen tip Made of acrylic fiber sliver core (porosity 50
%), length 15 mm Ink composition (total 100% by weight) Water-soluble dye (CI Direct Black-154) 4.5 Water-soluble dye (CI Direct Black-19) 1.5 Ethylene glycol 10.0 Glycerin 10.0 pH adjuster 0.3 Preservative (Proxel GXL) 0.5 Fixing resin (styrene acrylic acid resin, ammonia neutralized) 3.0 Surfactant (Ingen P, Daiichi Pharmaceutical Co., Ltd.) 0.2 Purified water Remainder Ink surface tension (25°C) 37 mN/m, ink viscosity coefficient (25°C) 8 mPa·s, amount impregnated into ink occluder 2.5 g

After assembly, the felt-tip pen obtained by the above-mentioned construction can be visually confirmed through the visual confirmation portion 12 that the ink is passing through the ink guide tube 30.
0, and the amount of ink flowing out as a felt-tip pen is almost constant until the ink runs out, just like a direct ink writing instrument, and it has been found that good lines can be drawn.
I continued writing until the ink had completely soaked into the pen.
The ink guide tube 30 is notified of the ink exhaustion, that is, the ink exhaustion sign from the ink occlusion body 20, through the visual confirmation part 12 formed on the barrel 10.
The ink supply end was detected simply and reliably by visually checking the ink supply end.
The ink flow rate suddenly decreased and it became impossible to write.

Example 2: Sign-Pen A sign-pen conforming to FIG. 5 was produced using the barrel, ink occlusion body, ink guide tube, relay core, pen tip relay core, pen tip, and ink composition described below. barrel made of polypropylene, diameter of large diameter part 10 mm, length of visible part 15 mm (parts other than the visible part are invisible due to a colored layer), total length 120 mm Ink occlusion body made of polyethylene terephthalate batting (porosity 80%), diameter 9 mm, length 60 mm Ink guide tube made of polypropylene, inner diameter 3 mm, length 20 mm, ink flow path cross-sectional area approximately 7 ^mm2 , surface tension of the ink guide tube material itself (25°C) 31 mN/m, length at which the rear end fits into the ink occlusion body 20 is 3 mm Relay core made of acrylic sliver (porosity 55%), diameter approximately 3 mm, length 30 mm, insertion part shape: cylindrical, acute angle part shape: conical Pen tip Relay core made of acrylic sliver (porosity 50%), diameter approximately 3 mm, length 8 mm, insertion part shape: cylindrical, acute angle part shape: conical, length 15 mm Pen tip: Consists of a sliver core of polyethylene terephthalate fiber (porosity 50%), length 15 mm Ink composition (total 100% by weight): Water-soluble dye (CI Direct Black-154) 5.0 Thiodiethanol 10.0 Glycerin 5.0 Urea 4.0 Surfactant (Dovanox 25N, Lion Corporation) 0.05 Purified water Rest Ink surface tension (25°C): 55 mN/m, ink viscosity coefficient (25°C): 2 mPa·s, amount impregnated into ink occlusion body: 2.5 g

After assembly of the felt-tip pen obtained with the above configuration, it was possible to visually confirm via the visual confirmation portion 12 that the ink was passing through the ink guide tube 30. The ink then penetrated the pen tip 40 via the pen tip relay core 28, and it was found that the amount of ink flowing out of the felt-tip pen remained constant until the ink was used up, just like in a direct-ink writing instrument, allowing for the drawing of good lines. Writing was continued until the ink impregnated in the ink occlusion body 20 was used up, and it was possible to easily and reliably detect that the ink had run out in the ink guide tube 30, i.e., the ink-out sign from the ink occlusion body 20, by visually confirming the ink guide tube 30 via the visual confirmation portion 12 formed on the barrel 10. Furthermore, after the ink guide tube 30 detected the end, the amount of ink flowing out suddenly decreased, making it impossible to write.

Example 3, Sign Pen A sign pen conforming to Figure 6 was produced using the following barrel, ink occlusion body, ink guide tube, relay core, pen tip and ink composition: barrel: made of polypropylene, large diameter part: 10 mm, visible part: 15 mm long (parts other than the visible part are invisible due to a colored layer), total length: 120 mm; ink occlusion body: made of polyethylene terephthalate padding (porosity: 80%), diameter: 9 mm, length: 60 mm; ink guide tube i) Long ink guide tube: made of polypropylene, inner diameter: 3 m
m, length 35 mm, ink flow path cross-sectional area approximately 7 mm ² , surface tension of the ink guide tube material itself (25°C) 31 mN/
m, and the length of the rear end portion inserted into the ink occlusion body 20 is 15 m
ii) Short ink guide tube: Made of polypropylene, inner diameter 3m
m, length 25 mm, ink flow path cross-sectional area approximately 7 mm ² , surface tension of the ink guide tube material itself (25°C) 31 mN/
m, the length of the rear end portion fitting into the ink occlusion body 20 is 5 mm. Relay core i) Long relay core: Made of polyethylene terephthalate sliver (porosity 55%), diameter 3 mm, length 20 mm, shape: cylindrical ii) Short relay core: Made of polyethylene terephthalate sliver (porosity 55%), diameter 3 mm, length 10 mm, shape: cylindrical iii) X ₁ : 10 mm, X ₂ : 15 mm Pen tip Made of acrylic fiber sliver core (porosity 50
%), length 15 mm Ink composition (total 100% by weight): Carbon black 6.0, Thiodiethanol 15.0, Glycerin 5.0, Urea 5.0, Surfactant (Pluronic PE3100, manufactured by BASF) 0.03, Purified water, balance Ink surface tension (25°C): 54 mN/m, ink viscosity coefficient (25°C): 2.5 mPa·s, amount impregnated into ink occlusion body: 2.5 g

After assembly, the felt-tip pen obtained by the above-mentioned construction can be visually confirmed through the visual confirmation part 12 that the ink passes through the ink guide tubes 31 and 32, and then penetrates into the pen tip 40, and it has been found that the felt-tip pen can draw good lines. When writing was continued until the ink impregnated in the ink occlusion body 20 was exhausted, it was first confirmed that there was no ink left in the ink guide tube 31, that is, the remaining ink amount sign (70% in this embodiment) from the ink occlusion body 20 was visible through the visual confirmation part 12 formed on the barrel 10.
By visually checking the ink guide tube 30 through the visual check portion 12 formed on the barrel 10, it was possible to easily and reliably detect the remaining amount of ink, and when writing was continued, it was found that the ink had run out in the ink guide tube 32, i.e., the end of the ink from the ink occlusion body 20 could be easily and reliably detected by visually checking the ink guide tube 32 through the visual check portion 12 formed on the barrel 10. In other respects, the same evaluation as in Example 1 was obtained.

[Example 4, Sign Pen] A sign pen conforming to Figure 7 was produced using the following barrel, ink occlusion body, ink guide tube, intermediate core, pen tip, rod-shaped body, and ink composition: barrel made of polypropylene, large diameter part 10 mm, visible part length 15 mm (parts other than the visible part are invisible due to a colored layer), total length 120 mm; ink occlusion body made of polyethylene terephthalate padding (porosity 80%), diameter 8 mm, length 60 mm; intermediate core made of acrylic sliver (porosity 55%), diameter approximately 3 mm, length 30 mm, insertion part shape: cylindrical, acute-angled part shape: conical; ink guide tube made of PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), inner diameter 3 mm, length 2
0 mm, ink flow path cross-sectional area approximately 7 mm ² , surface tension of the material of the ink guide tube itself (25°C) 20 mN/m, length of the rear end portion inserted into the ink occlusion body 20 3 mm rod-shaped body made of Teflon (registered trademark), diameter 1 mm, length 25 mm,
White nib made of acrylic fiber sliver core (porosity 50
%), length 15 mm Ink composition (total 100% by weight): Color pigment (CI Pigment Blue 15:3) 4.0, Thiodiethanol 5.0, Diethylene glycol 5.0, Isopropyl alcohol 3.0, Urea 3.0, Surfactant (Pluronic PE3100, manufactured by BASF) 0.03, Purified water, balance Ink surface tension (25°C): 55 mN/m, ink viscosity coefficient (25°C): 2 mPa·s, amount impregnated into ink occluder: 2.5 g

After assembly, the felt-tip pen obtained by the above-mentioned construction can be visually confirmed through the visual confirmation portion 12 that the ink is passing through the ink guide tube 35.
0, and it was found that the ink penetrated into the ink reservoir 20 and was able to draw good lines as a felt-tip pen. When writing was continued until the ink impregnated in the ink reservoir 20 was exhausted, it was found that the ink had run out in the ink guide tube 30, that is, the ink-out sign from the ink reservoir 20 could be easily and reliably detected by visually checking the white color of the rod-shaped body inserted into the ink guide tube 35 through the visual check portion 12 formed on the barrel 10. In other respects, the same evaluations as in Example 1 were obtained.

Example 5: Ballpoint Pen A ballpoint pen conforming to FIG. 9 was prepared using the barrel, ink occlusion body, ink guide tube, relay core, pen tip and ink composition described below. Tube: Polypropylene, large diameter 8 mm, visible part length 15 mm (areas outside the visible part are invisible due to a colored layer), total length 120 mm Ink occluder: Comprised of polyethylene terephthalate batting (porosity 80%), diameter 6 mm, length 60 mm Relay core: Comprised of polyethylene terephthalate sliver (porosity 55%), diameter 3 mm, length 20 mm, insertion part shape: cylindrical, acute-angled part shape: conical Ink guide tube: Polypropylene, inner diameter 3 mm, length 20 mm, ink flow path cross-sectional area approximately 7 ^mm2 , surface tension of the ink guide tube material itself (25°C) 31 mN/m, length of rear end inserted into ink occluder 20 3 mm Nib: Stainless steel, length 10 mm, ball diameter 0.5 mm Ink composition (total amount 100% by weight): Water-soluble dye (CI Direct Black-154) 5.0 Thiodiethanol 10.0 Glycerin 5.0 Urea 4.0 Surfactant (Dovanox 25N, Lion Corporation) 0.05 Purified water Remainder Ink surface tension (25°C) 55 mN/m, ink viscosity coefficient (25°C) 2 m Pa·s, amount impregnated into ink occlusion body 2.5 g

After assembly of the ballpoint pen obtained by the above-mentioned construction, it is possible to visually confirm through the visual confirmation portion 12 that the ink is passing through the ink guide tube 30.
0, and it was found that the ink penetrated into the ink reservoir 20, allowing good lines to be drawn as with a felt-tip pen. Writing was continued until the ink impregnated in the ink reservoir 20 was exhausted, and it was found that the ink had run out in the ink guide tube 30, that is, the ink-out sign from the ink reservoir 20 could be easily and reliably detected by visually checking the ink guide tube 30 through the visual check portion 12 formed on the barrel 10. In other respects, the same evaluation as in Example 1 was obtained.

Example 6: Sign-Tip Pen In Example 1 above, the ink occlusion body and the ink composition were replaced with the ink occlusion body and ink composition (oil-based ink) of the following configurations, and a sign-tip pen conforming to Figures 1 and 3 was produced. (Ink occluder) Composed of polyethylene terephthalate padding (porosity 80%), diameter 9 mm, length 60 mm [Ink composition (total amount 100% by weight)] n-propyl alcohol 75.0 Laropearl A-101 (aldehyde and urea condensate, manufactured by BASF) 7.5 Alresat KM400 (maleic acid resin, manufactured by Hoechst) 10.0 Victoria Blue BSA (dye, manufactured by Zeneca) 2.5 Rhodamine 6JHSA (dye, manufactured by Zeneca) 2.5 Flex YELLOW 105 (dye, manufactured by Zeneca) 2.5 Ink surface tension (25°C) approx. 25mN/m, ink viscosity coefficient (25°C) approx. 4mPa·s, amount of ink absorbent 2.5g

After assembly of the felt-tip pen obtained with the above configuration, it was possible to visually confirm via the visual confirmation portion 12 that the oil-based ink was passing through the ink guide tube 30, and then it penetrated into the pen tip 40. As a felt-tip pen, the amount of ink flowing out remained almost constant until the ink was used up, just like in a direct-ink writing instrument, and it was found that the pen was able to draw good lines. When writing was continued until the oil-based ink impregnated in the ink occlusion body 20 was used up, it was possible to easily and reliably detect that the ink had run out in the ink guide tube 30, that is, the ink-out sign from the ink occlusion body 20, by visually confirming the ink guide tube 30 via the visual confirmation portion 12 formed on the barrel 10. Furthermore, after the end was detected in the ink guide tube 30, the amount of ink flowing out suddenly decreased, making it impossible to write.

[0045]

According to the present invention, even though the writing instrument supplies ink impregnated in the ink reservoir inside the barrel to the pen tip, which is the writing part, it is possible to provide a writing instrument with a simple structure that allows easy and reliable visual detection of the ink end sign, and the amount of ink flow is almost constant until the ink runs out, just like in a direct ink writing instrument, allowing for the drawing of good lines. Furthermore, by having the relay core contact the inside of the ink reservoir over a length of 5% or more of the total length of the ink reservoir, it is possible to provide a writing instrument that can more efficiently and smoothly introduce the ink impregnated in the ink reservoir into the ink guide tube.

[Brief explanation of the drawings]

FIG. 1(a) is a longitudinal cross-sectional view of a writing instrument showing a first embodiment of the present invention, and FIG. 1(b) is a partial longitudinal cross-sectional view showing the main parts thereof, namely, the joining state of an ink guide tube, a relay core, and an ink impregnated body.

2A to 2H are cross-sectional views of various configurations of the ink guide tube 30. FIG.

FIG. 3 is a partial vertical cross-sectional view of a writing instrument showing a first embodiment of the present invention.

4A is a partial vertical cross-sectional view showing a modified example of the ink occlusion body 20, and FIG. 4B is a partial vertical cross-sectional view showing the barrel 10 and the ink occlusion body 2
10A is a partial vertical cross-sectional view showing a modified example of the shaft cylinder 10; FIG.

5A is a partial vertical cross-sectional view of a writing implement showing a second embodiment of the present invention, and FIG. 5B is a partial vertical cross-sectional view showing the main part thereof.

6A is a partial vertical cross-sectional view of a writing implement showing a third embodiment of the present invention, and FIG. 6B is a partial vertical cross-sectional view showing the main part thereof.

7A is a partial vertical cross-sectional view of a writing implement showing a fourth embodiment of the present invention, FIG. 7B is a perspective view showing the ink guide tube thereof, and FIG. 7C is a perspective view showing an ink guide tube showing another embodiment.

FIG. 8 is a partial vertical cross-sectional view of a writing implement showing a fifth embodiment of the present invention.

FIG. 9 is a partial vertical cross-sectional view of a writing implement showing a sixth embodiment of the present invention.

FIG. 10 is a partial vertical cross-sectional view of a writing implement showing a seventh embodiment of the present invention.

[Explanation of symbols]

A. Writing Instrument 10. Pen barrel 12. Visible portion 20. Ink reservoir 25. Lead core 30. Visible ink guide tube 40. Pen tip

───────────────────────────────────────────────────────── Continued from the front page (58) Researched fields (Int.Cl. ⁷ , DB name) B43K 5/00 - 8/24 B43K 27/00 - 27/12

Claims (18)

(57) [Claims] [Claim 1] A writing instrument that supplies ink impregnated in an ink absorbing body inside a barrel to the pen tip, which is the writing part, wherein the ink impregnated in the ink absorbing body is supplied to a visible ink guide tube via a relay core and then supplied to the pen tip via the ink guide tube, and the ink end sign from the ink absorbing body is detected by visually observing the ink guide tube through a visual observation part formed on the barrel. [Claim 2] A twin-type writing instrument that supplies ink impregnated in an ink absorbing body inside a barrel to each nib, which serves as the writing part, located on both sides of the barrel, wherein the ink supplied to either nib is supplied to a visible ink guide tube via a relay core and to the nib via the ink guide tube, and the ink end sign from the ink absorbing body is detected by visually observing the ink guide tube through a visual part formed on the barrel. 3. A writing implement according to claim 1 or 2, characterized in that the intermediate core is in contact with the inside of the ink occlusion body over a length of at least 5% of the total length of the ink occlusion body. 4. The writing implement according to claim 1, wherein the cross-sectional area of the intermediate core is 1 to 90% of the cross-sectional area of the ink occlusion body. 5. A writing implement according to claim 1, wherein the capillary force of the intermediate tip is greater than the capillary force of the ink occlusion body. [Claim 6] A writing instrument described in any one of claims 1 to 5, characterized in that the cross-sectional structure of the relay core has a structure having an inner layer portion and an outer layer portion, and the capillary force of the outer layer portion is greater than the capillary force of the inner layer portion. [Claim 7] A writing instrument described in any one of claims 1 to 6, characterized in that the ink supplied to the visible ink guide tube by the relay tip is further supplied to the pen tip via the pen tip relay tip. 8. The ink guide tube according to claim 1, wherein the surface tension of the surface of the ink guide tube that comes into contact with the ink or the material of the ink guide tube itself is smaller than the surface tension of the ink.
7. A writing instrument according to any one of 7. 9. The ink absorbing material according to claim 1, wherein the distribution of capillary force of the ink absorbing material is greater toward the pen tip side.
9. A writing instrument according to any one of claims 1 to 8. 10. A writing implement according to claim 1, wherein the inner diameter of the barrel is structured to become narrower as it approaches the pen tip. 11. A pen according to any one of claims 1 to 10, wherein a plurality of ribs are formed in the axial direction on the inner side of the barrel on the pen tip side.
1. A writing instrument according to any one of the preceding items. [Claim 12] A writing instrument described in any one of claims 1 to 11, wherein the relay core is made of one of a fiber bundle core, a porous resin particle body, and a sliver core, and these relay cores have a continuous flow path, so that the cross-sectional area of the ink flow path through the ink guide tube can be controlled while maintaining the apparent cross-sectional area of the ink guide tube. 13. An ink guide tube having ink visibility is filled with fiber bundles or porous resin particles having a surface tension lower than that of the ink and a different color from that of the ink,
13. The writing implement according to claim 1, wherein the cross-sectional area of the ink flow path through the ink guide tube and the flow resistance of the ink can be substantially controlled while maintaining the apparent cross-sectional area of the ink guide tube. 14. The writing implement according to claim 1, wherein a plurality of ink guide tubes are formed. 15. A writing implement according to any one of claims 1 to 14, characterized in that the length of the visible portion of the barrel is 1 mm or more and is equal to or less than the overall length of the writing implement. 16. The ink guide pipe has an ink flow passage cross-sectional area of 8.
x10^-2~80mm ²10. The method of claim 1, wherein
16. A writing instrument according to any one of claims 1 to 15. 17. The ink has a surface tension of 18 m at 25°C.
17. The writing implement according to claim 1, wherein the writing implement has a linearity of at least N/m. 18. The ink has a viscosity coefficient of 500 at 25°C.
18. The viscosity of the composition of claim 1, wherein the viscosity is 0.05 mPa·s or less.
1. A writing instrument according to any one of the preceding items.