Printing sheet for stamp

Information

  • Patent Grant
  • 6440549
  • Patent Number
    6,440,549
  • Date Filed
    Thursday, May 18, 2000
    24 years ago
  • Date Issued
    Tuesday, August 27, 2002
    22 years ago
Abstract
A printing sheet used in a stamp includes a porous layer in which ink can be impregnated and a fibrous layer provided to a side of the porous layer opposite to the pattern. The porous layer carries a pattern on a surface thereof, the pattern including a non-print portion which blocks the permeation of the ink and a print portion which allows the permeation of the ink. The fibrous layer prevents the deformation of the porous layer. The fibrous layer is so constituted that ink can be impregnated therein.
Description




BACKGROUND OF THE INVENTION




The present invention relates to a printing sheet used in a stamp.




As disclosed in Japanese Provisional Patent Publication Nos. 8-118771 and 8-207409, there is a type of stamp using a porous printing sheet in which ink can be impregnated. A pattern is formed on a surface of the printing sheet, including a print portion which allows the permeation of ink and a non-print portion which block the permeation of ink.




On using the stamp, a user holds the stamp and forces the stamp to a media (such as a paper) so that the surface of the printing sheet is urged against the media. With this, ink impregnated in the printing sheet is permeated through the print portion of the printing sheet and transferred onto the media. Therefore, it is possible to repeatedly print images on the media for several times without supplying ink to the printing sheet.




In order to reduce the cost for producing the printing sheet, the conventional printing sheet is made thin. Thus, when ink is impregnated in the printing sheet, the printing sheet may be swollen. In such case, a surface of the printing sheet may be deformed, which causes the printed image to be blurred.




Further, since the printing sheet is made thin, an amount of ink to be impregnated in the printing sheet is relatively small. Thus, it is necessary to further provide a sponge-like member in the stamp. Accordingly, the number of parts of the stamp is increased and the producing cost thereof is also increased. In order to increase an amount of ink to be impregnated in the printing sheet, it is alternatively possible to make the printing sheet thicker. However, since the pores of the printing sheet are generally minute, the time required to fully impregnate ink in the printing sheet becomes longer as the printing sheet becomes thicker.




Furthermore, if the printing sheet is made thin, the elasticity thereof is relatively small. Accordingly, when the printing sheet is urged onto the media, a pressure distribution of the printing sheet may not be uniform. In order to solve this problem, it is necessary to further provide a cushion member in the stamp. Thus, the number of parts is increased and the producing cost thereof is also increased.




SUMMARY OF THE INVENTION




Therefore, the first object of the present invention is to prevent a deformation of a surface of a printing sheet. The second object of the present invention is to increase an amount of ink impregnated in the printing sheet without increasing the number of parts. The third object of the present invention is to make a pressure distribution of the printing sheet uniform.




According to one aspect of the present invention, there is provided a printing sheet including (1) a porous layer in which ink can be impregnated and (2) a fibrous layer made of fibers. The fibrous layer is provided to one side of the porous layer. The porous layer carries a pattern on a surface thereof. The pattern includes a non-print portion which blocks the permeation of the ink and a print portion which allows the permeation of the ink.




When such printing sheet is used to form image, the printing sheet is mounted to a stamp. The user holds the stamp and forces the stamp to a media (such as a paper) so that the surface of the porous layer is urged against the surface of the media. Ink (impregnated at least in the porous layer) permeates the printing portion of the porous layer, and is transferred onto the media. Thus, image is formed on the media.




In order to accomplish the first object of the present invention, the fibrous layer is so constructed as to prevent a deformation of the porous layer. With such an arrangement, even if the printing sheet is swollen, a surface of the printing sheet is not deformed. Thus, it is prevented that the printed image (on a media) is blurred.




In order to accomplish the second object of the present invention, the fibrous layer is so constituted that ink can be impregnated therein. With such an arrangement, an amount of ink to be impregnated in the printing sheet can be increased, without providing a sponge-like member or the like. Further, since it is no longer necessary to make the printing sheet thicker (for increasing the amount of impregnated ink), the time required to fully impregnate ink throughout the printing sheet does not become long.




In order to accomplish the third object of the present invention, the fibrous layer has a certain elasticity. With such an arrangement, a pressure distribution of the printing sheet (when the printing sheet is urged onto the media) is uniform, even if the porous layer is relatively thin.




Preferably, the fibrous layer includes one of a non-woven fabric and a textile having raised fabrics. In case where the porous layer includes a foamed resin, it is preferred that the foamed resin of the porous layer and the fabric of the fibrous layer entangle with each other.




According to another aspect of the present invention, there is provided a base sheet (used to produce the printing sheet) including a porous layer in which ink can be impregnated and a fibrous layer made of fibers. A pattern can be formed on a surface of the porous layer, by heating the surface according to desired image.











BRIEF DESCRIPTION OF DRAWINGS





FIGS. 1A and 1B

are a perspective view and a sectional view of a base sheet of a printing sheet according to an embodiment of the present invention;





FIGS. 2A and 2B

are a plan view and a sectional view of a stamp producing device for producing the printing sheet;





FIG. 3

is a perspective view of a tray of the stamp producing device of

FIGS. 2A and 2B

;





FIG. 4

is a perspective view of the stamp producing device of

FIGS. 2A and 2B

;





FIGS. 5A

,


5


B and


5


C are sectional views illustrating the producing process of the printing sheet;





FIG. 6

is a perspective view of the printing sheet;





FIG. 7

is a sectional view of a stamp;





FIGS. 8A and 8B

are an enlarged sectional view of a fibrous portion of the stamp, and





FIG. 9

is a flowchart outlining an exemplary method of forming a base sheet used to produce a printing sheet.











DESCRIPTION OF THE EMBODIMENT




An embodiment of the present invention is described with reference to the accompanying drawings.





FIGS. 1A and 1B

are a perspective view and a sectional view of a base sheet


12


of a printing sheet of the embodiment. The base sheet


12


includes a porous layer


12




a


and a fibrous layer


12




b


integrally provided to the lower side of the porous layer


12




a.


The porous layer


12




a


is made of a porous material in which ink can be impregnate. For example, the porous layer


12




a


is made of foamed resin such as polyolefin-based resin, polyvinyl chloride-based resin or polyurethane-based resin. The porous layer


12




a


has a certain flexibility and softness, and has an substantially uniform thickness of approximately 0.2 mm to 0.8 mm.




The porous layer


12




a


contains carbon grains uniformly dispersed therein. When the surface of the base sheet


12


is heated, the heated surface melts such that pores near the surface thereof are sealed. Thus, when the porous layer


12




a


is selectively exposed to the electromagnetic waves (such as infrared rays) according to desired image, the heated surface of the porous layer


12




a


becomes a non-print portion which blocks the permeation of ink, while the other portion becomes a print portion which allows the permeation of ink. The content of the carbon grains in the porous layer


12




a


is from 0.01 to 15 wt %. With such an arrangement, the porous layer


12




a


is gray and, when heated, turns black. Accordingly, it can be confirmed which of various colors of ink has been impregnated in the porous layer


12




a.


Further, since the carbon is greater than or equal to 0.01 wt %, the porous layer


12




a


is easily heated (such that the pores at the surface thereof are sealed) by a standard flash bulb.




The fibrous layer


12




b


may be made of a non-woven fabric that is made by adhering or entangling fibers mechanically, chemically, or thermally. For example, the fibrous layer


12




b


is made of a felt that is made from nylon fibers, polyester fibers, or polyolefin fibers. Alternatively, the fibrous layer


12




b


can be made of a raised fabric that is made by raising nap on textile. The porous layer


12




a


and the fibrous layer


12




b


may, for example, be fixed with each other in such a manner that the foamed resin material (of the porous layer


12




a


) is entangled with the fabrics of the fibrous layer


12




b.


With this, the porous layer


12




a


and the fibrous layer


12




b


are attached to form the base sheet


12


. This is one example in which the porous layer


12




a


is attached to the fibrous layer


12




b


by being formed integrally with the fibrous layer


12




b.






In order to attach the fibrous layer


12




b


to the porous layer


12




a,


various other methods can be employed. For example, the layers may be conjugated using heat, such as by fusing, cemented using adhesive, or attached by any other suitable method.




A method of forming the base sheet


12


is described with reference to FIG.


9


. First, in step


1000


, material that is to form the porous layer


12




a


is dissolved with a solvent. Then, in step


2000


, the dissolved material, which is, for example, a mixture of resin and a water-soluble material, such as NaCl, is coated on the fibrous layer


12




b.


At this stage, the coated layer may not yet exhibit porosity. Therefore, in step


3000


, the fibrous layer


12




b


coated with the dissolved material is soaked in water. By soaking the fibrous layer


12




b


coated with the dissolved material in water, the solvent is washed away, and the water-soluble material, such as NaCl, is dissolved out of the coated layer, leaving hollow portions to cause porosity. This results in the porous layer


12




a.


Furthermore, at this stage, a “framework” of the porous layer


12




a


is formed because the coated layer becomes hardened. Then, in step


4000


, the porous layer


12




a


and the fibrous layer


12




b


are heat treated and/or dried, allowing the water in the porous layer and fibrous layer to evaporate. The process then ends in step


5000


.




Since the porous layer


12




a


was applied to the fibrous layer


12




b


in a dissolved form and then hardened, the hardened material of the porous layer


12




a


entangles fibers of the fibrous layer


12




b,


thus attaching the fibrous layer


12




b


to the porous layer


12




a.






A method for producing a printing sheet is described.

FIGS. 2A and 2B

are a plan view and a sectional view of a stamp producing device


1


used for producing the printing sheet. The stamp producing device


1


includes a unit body


3


accommodating a flash bulb


6


and a tray


2


detachably provided to the unit body


3


.





FIG. 3

is a perspective view of the tray


2


.

FIG. 4

is a perspective view separately showing the unit body


3


and the tray


2


. The tray


2


includes a tray body


2




a


and a transparent cover


2




b


swingably provided to the tray body


2




a.


A rectangular concave


2




d


is provided at the center portion of the tray body


2




a,


for placing the base sheet


12


and other two sheets (an original sheet


11


and an intermediate sheet


13


) thereon. The transparent cover


2




b


is pivoted by a pin


2




g


disposed at one side of the tray body


2




a


so that the transparent cover


2




b


can be opened or closed. In order to lock the transparent cover


2




b


in a closed state, a lock lever


2




c


is provided to the side (of the tray body


2




a


) opposite to the pin


2




g.


An engaging portion


2




f


provided at the tip of the transparent cover


2




b.


When the lock lever


2




c


is swing to an erected position (as shown in FIG.


4


), the lock lever


2




c


holds the engaging portion


2




f


of the transparent cover


2




b.


When the lock lever


2




c


is swung to a laid position (as shown in FIG.


3


), the lock lever


2




c


releases the engaging portion


2




f


so that the transparent cover


2




b


can be opened. The transparent cover


2




b


is made of a transparent acrylic resin or the like. The transparent cover


2




b


is provided with a transparent pressing portion


2




e


at the bottom thereof, which urges the base sheet


12


, the original sheet


11


and the intermediate sheet


13


against the bottom of the concave


2




d.






As shown in

FIG. 4

, the unit body


3


includes a box-shaped case


4


. An insertion opening


4




a


is formed on the lower portion of the front wall of the case


4


. The tray


2


can be inserted into the unit body


3


through the insertion opening


4




a.


A truncated-pyramid-shaped chamber


6


is formed in the upper portion of the case


4


. The inner surfaces of the chamber


5


are covered with a film such as aluminum foil, which has a large reflectivity. As shown in

FIG. 2A

, the flash bulb


6


is detachably mounted to a mounting portion


5




a


formed on one side wall of the chamber


6


. Batteries


8


are provided in the case


4


, for supplying power to the flash bulb


6


. The batteries


8


are connected to the flash bulb


6


via a contact member


7


provided therebetween. A switch


9


is provided in the vicinity of an internal wall of the case


4


. When the tray


2


is inserted through the insertion opening


4




a


and is accommodated in the unit body


3


, the switch


9


is urged by the tray


2


to be turned ON. Then, power is supplied (from the batteries


8


) to the flash bulb


6


, so that the flash bulb


6


flashes.




The method for producing the printing sheet is described. FIGS


5


A,


5


B and


5


C are schematic views illustrating the method for producing the printing sheet.




First, the original sheet


11


carrying a desired image is described. As shown in

FIG. 5A

, the original sheet


11


includes a transparent sheet


11




a


and a photochromic layer


11




b


formed on the lower surface of the transparent base sheet


11




a.


The transparent sheet


11




a


has substantially uniform thickness and is made of synthetic resin such as polyethylene terephthalate (PET), polyvinyl chloride, or acrylonitrile-butadiene-styrene (ABS) resin. The melting point of the transparent sheet


11




a


is higher than the melting point of the base sheet


12


. In particular, if the transparent sheet


11




a


is made of PET, the melting point thereof is approximately 230° C. Comparatively, the melting point of the base sheet


12


is approximately 120° C. (in case the base sheet


12


is made of plasticized polyurethane-based resin) or approximately 70° C. (in case the base sheet


12


is made of plasticized polyolefin-based resin). Thus, when the original sheet


11


and the base sheet


12


are laminated and heated, and when the base sheet


12


melts, the original sheet


11


does not melt.




The photochromic layer


11




b


has substantially uniform thickness. A shielding portion


11




c


is formed on the photochromic layer


11




b,


according to a desired image.




Although the shielding portion


11




c


has already been formed before the producing of the printing sheet


14


, the producing process of the shielding portion


11




c


is shortly described. The photochromic layer


11




b


is formed by means of applying (or impregnating) an organic photochromic ink (manufactured by Teikoku Ink Kabushiki Kaisha) on the surface of the transparent sheet


11




a.


The photochromic layer


11




b


is normally colorless and transparent but turns blue and non-transparent when exposed to electromagnetic waves including ultraviolet rays. The photochromic layer


11




b


is selectively exposed to electromagnetic waves including ultraviolet rays, with a negative film placed thereon. With this, the exposed portion of the photochromic layer


11




b


turns blue and non-transparent. Thus, a shielding portion


11




c


is formed on the photochromic layer


11




b


according to desired image. Further, the photochromic layer


11




b


has a characteristics that the photochromic layer


11




b


returns colorless and transparent when the photochromic layer


11




b


is shielded from the radiation of ultraviolet rays for a predetermined time. Therefore, the original sheet


11


can be used as a new original sheet, enabling a user to form new image thereon. The original sheet


11


can be reused many times as long as the photochromic ink is not deteriorated.




The intermediate sheet


13


is placed between the base sheet


12


and the original sheet


11


. The intermediate sheet


13


is transparent and its thickness is approximately 0.025 mm to 0.2 mm. The intermediate sheet


13


is made of PET and the melting point thereof is approximately 230° C., which is higher than that of the base sheet


12


. Therefore, when the intermediate sheet


13


and the base sheet


12


are laminated and heated, and when the base sheet


12


melts due to heating, the intermediate sheet


13


does not melt.




Before producing the printing sheet, the tray


2


is removed from the unit body


3


. Then, the transparent cover


2




b


of the tray


2


is opened (as shown in FIG.


3


), by operating the lock lever


2




c


to release the engaging portion


2




f.


Then, the base sheet


12


, the intermediate sheet


13


and the original sheet


11


are placed in the concave


2




d


of the tray


2


. In this state, as shown in

FIG. 5A

, the base sheet


12


is placed so that the fibrous layer


12




b


is faced downward and that


12




a


of the base sheet


12


. The original sheet


11


is overlaid on the intermediate sheet


13


so that the photochromic layer


11




b


of the original sheet


11


contacts the intermediate sheet


13


.




After the base sheet


12


, the intermediate sheet


13


and the original sheet


11


are placed in the tray


2


, the transparent cover


2




b


is closed. The transparent cover


2




b


is locked by the engagement of the lock lever


2




c


and the engaging portion


2




f.


In this state, the pressing portion


2




e


of the transparent cover


2




b


urges the original sheet


11


against the base sheet


12


. Then, the tray


2


is inserted into the unit body


3


through the insertion opening


4




a


(FIG.


2


B). When the tray


2


is inserted into the unit body


3


, the switch


9


is turned on, so that power is supplied from the batteries


8


to the flash bulb


6


. With this, the flash bulb irradiates electromagnetic waves including infrared rays R.




As shown in

FIG. 5B

, when the flash bulbs


6


flashes, the infrared rays R pass through the transparent cover


2




b,


the pressing portion


2




e


and the transparent sheet


11




a


of the original sheet


11


, and irradiated on the photochromic layer


11




b.


The shielding portion


11




c


of the photochromic layer


11




b


blocks the infrared rays (R


1


in

FIG. 5B

) and other portion of the photochromic layer


11




b


allows the infrared rays (R


2


in

FIG. 5B

) to pass. The infrared rays passing through the photochromic layer


11




b


reach the porous layer


12




a,


which heats the porous layer


12


to cause pores thereof to melt and be sealed. Accordingly, a non-print portion


12




c


is formed on the porous layer


12




a,


which blocks the permeation of ink. On the other hand, since the infrared ray R


1


blocked by the shielding portion


11




c


do not reach the porous layer


12




a,


a print portion


12




d


is formed on the porous resin payer


12




a,


which allows the permeation of ink. As shown in

FIG. 5C

, the porous layer


12




a


(including the print portion


12




d


and the non-print portion


12




c


) and the fibrous layer


12




b


constitute a printing sheet


14


.

FIG. 6

is a perspective view of the printing sheet


14


. The print portion


12




d


and the non-print portion


12




c


are formed on the porous layer


12




a


according to a desired pattern, for example, “E”.




Accordingly, the printing sheet


14


including a porous layer


12




a


carrying a pattern (the print portion


12




d


and the non-print portion


12




c


) and the fibrous layer


12




b


is formed by the above described process.




In the above described process, although the shielding portion


11




c


of the photochromic layer


11


is heated by the irradiation of the infrared rays, the heat is released via the intermediate sheet


13


(which is in contact with the surface of the photochromic layer


11


). Thus, it is prevented that a part of the porous layer


12




a


which is to be the print portion


12




c


(corresponding to the shielding portion


11




c


) is unintentionally heated.




The structure of a stamp


20


using the printing sheet


14


is described.

FIG. 7

is a sectional view showing a stamp


20


. The stamp


20


includes a handle


24


held by the user and a stamp body


21


provided to the lower end of the grip


24


. The stamp body


21


has a recess


22


which opens at the bottom end of the stamp body


21


, so that the printing sheet


14


is fit into the recess


22


. The stamp body


21


is made of plastic, metal or the like. A fibrous portion


23


is provided in the upper portion of the recess


22


, for holding the printing sheet


14


.

FIG. 8A

is a schematically enlarged view showing the fibrous portion


23


. As shown in

FIG. 8A

, the fibrous portion


23


includes a large number of fibers


23




a


planted on the upper wall of the recess


22


and extending downward therefrom. The fibers


23




a


are made of synthetic resin or the like. Each fiber


23




a


has hook-shaped curved portion


23




b


at the lower end thereof. Alternatively, as shown in

FIG. 8B

, it is possible that each fiber


23




a


has an arrowhead-shaped tip.




The handle


24


is detachably provided to the stamp body


21


. The stamp body


21


is provided with an ink supply port


25


beneath the handle


24


, extends downward to the upper wall of the recess


22


. When the handle


24


is detached from the stamp body


21


, the ink supply port


25


is opened. In this state, the user can supply ink to the ink sheet


14


through the ink supply port


25


.




As shown in

FIG. 7

, the printing sheet


14


is mounted to the recess


22


in such a manner that the non-woven fabric (or the raised fabric) of the fibrous layer


12




b


of the printing sheet


14


is entangled with the hook-shaped (or arrowhead-shaped) lower end of the fibers


23




a


of the fibrous portion


23


. Thus, the printing sheet


14


can be mounted to the stamp body


21


, by simply urging the printing sheet


14


against the fibrous portion


23


.




On using the stamp


20


, the user holds the handle


24


and forces the stamp


20


to a not-shown media such as a paper so that the lower surface (printing surface) of the printing sheet


14


is urged against the media. With this, ink impregnated in the fibrous layer


12




b


is permeated through the print portion


12




c


of the printing sheet


12


and transferred onto the media. Due to the elasticity of the fibrous layer


12




b,


a pressure distribution of the printing sheet


14


is uniform, even if the porous layer


12




a


is swollen.




On replacing the printing sheet


14


, the printing sheet


14


can be easily removed from the recess


22


by simply peeling the printing sheet


14


from the fibrous portion


23


. With this, the non-woven fabric (or the raised fabric) of the fibrous layer


12




b


of the printing sheet


14


is released from the fibers


23




a


of the fibrous portion


23


. Therefore, a various kind of printing sheets


14


can be mounted to the stamp body


21


, to form various kinds of images on the media.




The fibrous layer


12




b


has a characteristics such that the fibrous layer


12




b


is not swollen even if ink is impregnated therein. Since the porous layer


12




a


is integrally formed with the fibrous layer


12




b,


the deformation of the surface of the porous layer


12




a


is prevented, even if the porous layer


12




a


is swollen.




The amount of ink impregnated in the fibrous layer


12




b


is larger than that of the porous layer


12




a.


Thus, it is not necessary to provide a separate ink impregnating member (sponge-like) mat or the like) other than the printing sheet


14


. Further, since spaces between fabrics of the fibrous layer


12




b


is larger than pores of the porous layer


12




b,


the ink can be impregnated into the printing sheet


14


in a short time.




Furthermore, since the fibrous layer


12




b


has an elasticity, the printing sheet


14


also has an elasticity. Due to the elasticity of the printing sheet


14


, it is possible to apply a uniform pressure throughout the printing surface without providing a separate cushion member. Thus, a clear image is formed on a media.




Although the structure of a present invention is described herein with respect to the preferred embodiment, many modifications and changes can be made without departing from the spirit and scope of the invention.




For example, in the above-described embodiment, the flash bulb


6


is used as a heat source for melting the porous layer


12




a


of the base sheet


12


. However, the flash bulb


6


can be replaced by a xenon tube or other light source which emits infrared rays. Also, the flash bulb


6


can be replaced by a heat generator such as a thermal head.




Further, the original sheet


11


can be replaced by a tracing paper or other paper which allows the electromagnetic waves to pass and which carries an image with shielding ink of a desired color (such as, black, white, gold, and silver). Still further, the porous layer


12




a


of the base sheet


12


can be made of any foamed material which can be formed flexible a porous sheet. Furthermore, carbon grains dispersed in the porous layer


12




a


can be replaced by any substance which generated heat due to heating when irradiated by electromagnetic waves (for example, a high-molecular substance such as silver chloride and silver bromide, or a light energy absorbing substance).




The present disclosure relates to subject matter contained in Japanese Patent Application Nos. HEI 9-78599, filed on Mar. 28, 1997 and HEI 9-79665, filed on Mar. 31, 1997 which are expressly incorporated herein by reference in its entirety.



Claims
  • 1. A printing sheet used in a stamp, said printing sheet comprising:a porous layer in which ink can be impregnated, said porous layer tending to deform when impregnated with ink; and a fibrous layer made of fibers, said fibrous layer being attached to one side of said porous layer and reducing the deformation of the porous layer due to ink impregnation; wherein said porous layer carries a pattern on a surface thereof, said pattern including a non-print portion which blocks permeation of said ink and a print portion which allows permeation of said ink.
  • 2. The printing sheet according to claim 1, wherein said fibrous layer is so constituted that ink can be impregnated therein.
  • 3. The printing sheet according to claim 1, wherein said fibrous layer has elasticity.
  • 4. The printing sheet according to claim 1, wherein said fibrous layer comprises one of a non-woven fabric and a textile having raised fabrics.
  • 5. The printing sheet according to claim 1, wherein said porous layer comprises a foamed resin, andwherein said foamed resin of said porous layer and said fibers of said fibrous layer entangle with each other.
  • 6. The printing sheet according to claim 1, wherein said porous layer includes a heat-generating material which generates heat when exposed to electromagnetic waves.
  • 7. The printing sheet according to claim 6, wherein said porous layer includes carbon grains, and said carbon grains generate heat when exposed to infrared rays.
  • 8. A base sheet used to produce a printing sheet used in a stamp, said base sheet comprising:a porous layer in which ink can be impregnated, said porous layer tending to deform when impregnated with ink; and a fibrous layer made of fibers, said fibrous layer being attached to one side of said porous layer and reducing the deformation of said porous layer due to ink impregnation; wherein a pattern can be formed on a surface of said porous layer by heating said surface according to a desired image, said pattern including a non-print portion which blocks permeation of said ink and a print portion which allows permeation of said ink.
  • 9. The base sheet according to claim 8, wherein said fibrous layer is so constituted that ink can be impregnated therein.
  • 10. The base sheet according to claim 8, wherein said fibrous layer has elasticity.
  • 11. The base sheet according to claim 8, wherein said fibrous layer comprises one of a non-woven fabric and a textile having raised fabrics.
  • 12. The base sheet according to claim 8, wherein said porous layer comprises a foamed resin, andwherein said foamed resin of said porous layer and said fibers of said fibrous layer entangle with each other.
  • 13. The base sheet according to claim 8, wherein said porous layer includes a heat-generating material which generates heat when exposed to electromagnetic waves.
  • 14. The printing sheet according to claim 13, wherein said porous layer includes carbon grains, and said carbon grains generate heat when exposed to infrared rays.
  • 15. A base sheet used to produce a printing sheet used in a stamp, said base sheet comprising:a porous layer in which ink can be impregnated, said porous layer tending to deform when impregnated with ink; and a deformation reducing material which is attached to one side of said porous layer and reduces the deformation of said porous layer due to ink impregnation; wherein a pattern can be formed on a surface of said porous layer by heating said surface according to a desired image, said pattern including a non-print portion which blocks permeation of said ink and a print portion which allows permeation of said ink.
  • 16. A stamp comprising:a stamp body; and a printing sheet mounted to said stamp body, wherein said printing sheet comprises a porous layer in which ink can be impregnated and a fibrous layer made of fibers, the fibrous layer being attached to one side of said porous layer, the porous layer tending to deform when impregnated with ink and the fibrous layer reducing the deformation of the porous layer due to ink impregnation; wherein said porous layer carries a pattern on a surface thereof, said pattern including a non-print portion which blocks permeation of said ink and a print portion which allows permeation of said ink.
  • 17. The stamp according to claim 16, further comprising a fibrous portion provided to said stamp body, said fibrous layer being fixed to said fibrous portion.
  • 18. The stamp according to claim 16, wherein said fibrous layer has elasticity.
  • 19. The stamp according to claim 16, wherein said fibrous layer comprises one of a non-woven fabric and a textile having raised fabrics.
  • 20. The printing sheet according to claim 16, wherein said porous layer comprises a foamed resin, andwherein said foamed resin of said porous layer and said fibers of said fibrous layer entangle with each other.
  • 21. The base sheet according to claim 15, wherein said porous layer includes a heat-generating material which generates heat when exposed to electromagnetic waves.
  • 22. The base sheet according to claim 21, wherein said porous layer includes carbon grains, and said carbon grains generate heat when exposed to infrared rays.
  • 23. A printing sheet used in a stamp according to claim 1, wherein said fibrous layer is attached to said porous layer by conjugation utilizing heat.
  • 24. A printing sheet used in a stamp according to claim 1, wherein said fibrous layer is attached to said porous layer by adhesive.
  • 25. A printing sheet used in a stamp according to claim 1, wherein said porous layer is attached to said fibrous layer by being formed integrally with said fibrous layer.
  • 26. A method for forming the base sheet of claim 8, comprising:dissolving material used to form a porous layer with a solvent; coating said dissolved material on a fibrous layer; soaking said fibrous layer coated with said dissolved material in water to remove a water-soluble material, thereby leaving hollow portions in said material to form a porous layer; and performing at least one of drying and heat treating to said porous layer and said fibrous layer.
  • 27. A base sheet according to claim 8, wherein said fibrous layer is attached to said porous layer by conjugation utilizing heat.
  • 28. A base sheet according to claim 8, wherein said fibrous layer is attached to said porous layer by adhesive.
  • 29. A base sheet according to claim 8, wherein said porous layer is attached to said fibrous layer by being formed integrally with said fibrous layer.
  • 30. A base sheet according to claim 8, wherein said fibrous layer is directly attached to said porous layer.
  • 31. A base sheet according to claim 15, wherein said deformation reducing material is attached to said porous layer by conjugation utilizing heat.
  • 32. A base sheet according to claim 15, wherein said deformation reducing material is attached to said porous layer by adhesive.
  • 33. A base sheet according to claim 15, wherein said porous layer is attached to said deformation reducing material by being formed integrally with said deformation reducing material.
  • 34. A base sheet according to claim 15, wherein said deformation reducing material is directly attached to said porous layer.
  • 35. A stamp according to claim 16, wherein said fibrous layer is attached to said porous layer by conjugation utilizing heat.
  • 36. A stamp according to claim 16, wherein said fibrous layer is attached to said porous layer by adhesive.
  • 37. A stamp according to claim 16, wherein said porous layer is attached to said fibrous layer by being formed integrally with said fibrous layer.
  • 38. A stamp according to claim 16, wherein said fibrous layer is directly attached to said porous layer.
  • 39. A printing sheet used in a stamp according to claim 1, wherein said fibrous layer is directly attached to said porous layer.
Priority Claims (2)
Number Date Country Kind
9-78599 Mar 1997 JP
9-79665 Mar 1997 JP
Parent Case Info

This is a Continuation-in-Part of application Ser. No. 09/047,486 filed Mar. 25, 1998 abandoned. The entire disclosure of the prior application(s) is hereby incorporated by reference herein in its entirety.

US Referenced Citations (3)
Number Name Date Kind
5392711 Kainuma Feb 1995 A
5611279 Ando et al. Mar 1997 A
5771806 Imamaki Jun 1998 A
Foreign Referenced Citations (4)
Number Date Country
2 297 717 Aug 1996 GB
8-118771 May 1996 JP
8-207409 Aug 1996 JP
WO 9622874 Aug 1996 WO
Continuation in Parts (1)
Number Date Country
Parent 09/047486 Mar 1998 US
Child 09/572335 US