Patents by Inventor Keiichi Shiokawa

Keiichi Shiokawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6787203
    Abstract: A thermal transfer recording medium including at least a substrate; a separation layer located overlying the substrate; and an ink layer located overlying the separation layer, wherein the separation layer includes at least a wax including a polyethylene wax, and wherein the ink layer includes at least a thermoplastic saturated polyester resin having a hydroxyl value of from 20 to 60 mgKOH/g; and an oxidized polyethylene having an acid value not greater than 5 mgKOH/g.
    Type: Grant
    Filed: August 20, 2002
    Date of Patent: September 7, 2004
    Assignee: Ricoh Company Limited
    Inventors: Katsunori Hiroishi, Keiichi Shiokawa, Takayuki Sasaki
  • Publication number: 20030054144
    Abstract: A thermal transfer recording medium including at least a substrate; a separation layer located overlying the substrate; and an ink layer located overlying the separation layer, wherein the separation layer includes at least a wax including a polyethylene wax, and wherein the ink layer includes at least a thermoplastic saturated polyester resin having a hydroxyl value of from 20 to 60 mgKOH/g; and an oxidized polyethylene having an acid value not greater than 5 mgKOH/g.
    Type: Application
    Filed: August 20, 2002
    Publication date: March 20, 2003
    Inventors: Katsunori Hiroishi, Keiichi Shiokawa, Takayuki Sasaki
  • Publication number: 20020097316
    Abstract: A thermal image transfer recording method includes the steps of holding a thermal image transfer recording medium having a support and a thermal transfer layer formed thereon and an image receiving member between an edge thermal head for use in a line printer and a platen roller in such a fashion that the thermal transfer layer of the recording medium comes in contact with the image receiving member with the application of a tension to the thermal image transfer recording medium, and transferring an image from the thermal transfer layer of the recording medium to the image receiving member by the application of heat to the recording medium using the thermal head, the thermal image transfer recording medium having a dynamic elasticity modulus in a range of 1×106 to 1×1010 at 70° C.
    Type: Application
    Filed: December 5, 1997
    Publication date: July 25, 2002
    Applicant: RICOH COMPANY, LTD.
    Inventors: KEIICHI SHIOKAWA, YOSHIAKI YAMADA, YASUMITSU KUGA
  • Patent number: 5952103
    Abstract: A thermal image transfer recording medium includes a substrate, a thermal image transfer ink layer provided on the substrate, and a heat resistant protective layer which is provided on the back side of the substrate, opposite to the thermal transfer ink layer with respect to the substrate, with which a thermal head comes into contact. The heat resistant protective layer is made of an organic polymeric material free from cross-linking structure, with a film strength of 10 mN or more, and the surface of the heat resistant protective layer has a contact angle with pure water of 95.degree. or more and a dynamic coefficient of friction of 0.07 or loss. The heat resistant protective layer may also be made of a modified copolymer containing (a) a main backbone chain polymer including an active-hydrogen-containing polymer which encompasses no cellulose compounds and (b) a side chain polymer which is a copolymer of a reactive silicone and a vinyl monomer.
    Type: Grant
    Filed: November 10, 1997
    Date of Patent: September 14, 1999
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiichi Shiokawa, Hiroshi Tohmatsu, Yoji Ide, Yoichi Iwaki, Shigekazu Teranishi, Susumu Kawakami, Hironori Hata
  • Patent number: 5800914
    Abstract: A thermal image transfer recording medium includes a heat resistant substrate; an intermediate layer with a voidage of 20% or less, which includes a granular thermofusible material and a thermoplastic resin, formed on the heat resistant substrate; and a thermal image transfer ink layer containing a coloring agent, formed on the intermediate layer.
    Type: Grant
    Filed: June 4, 1996
    Date of Patent: September 1, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiichi Shiokawa, Yasumitsu Kuga, Naoshi Yamamoto
  • Patent number: 5773153
    Abstract: A thermal image transfer recording medium includes a substrate, a thermal image transfer ink layer provided on the substrate, and a heat resistant protective layer which is provided on the back side of the substrate, opposite to the thermal transfer ink layer with respect to the substrate, with which a thermal head comes into contact. The heat resistant protective layer is made of an organic polymeric material free from cross-linking structure, with a film strength of 10 mN or more, and the surface of the heat resistant protective layer has a contact angle with pure water of 95.degree. or more and a dynamic coefficient of friction of 0.07 or less. The heat resistant protective layer may also be made of a modified copolymer containing (a) a main backbone chain polymer including an active-hydrogen-containing polymer which encompasses no cellulose compounds and (b) a side chain polymer which is a copolymer of a reactive silicone and a vinyl monomer.
    Type: Grant
    Filed: September 8, 1995
    Date of Patent: June 30, 1998
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiichi Shiokawa, Hiroshi Tohmatsu, Yoji Ide, Yoichi Iwaki, Shigekazu Teranishi, Susumu Kawakami, Hironori Hata
  • Patent number: 5428372
    Abstract: A multiple-use thermal image transfer recording method includes the step of transferring a thermal image transfer ink component a plurality of times to an image-receiving medium from at least an identical portion of a thermal image transfer recording medium composed of a support and a thermal image transfer ink layer formed thereon, with the application of heat thereto. The thermal image transfer ink layer is composed of the thermal image transfer ink component mainly containing a coloring agent and a thermofusible material, and a porous resin component which is not thermally transferable, with both components having mutual releasability. The image-receiving medium has a recording surface, with the product of the absorption coefficient (Ka) of the recording surface measured by the Bristow Method (J. TAPPI. No. 51 - 87) at a pressure of 0.
    Type: Grant
    Filed: November 4, 1992
    Date of Patent: June 27, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Mihoko Akiyama, Keiichi Shiokawa, Yoji Ide
  • Patent number: 5409758
    Abstract: A thermal image transfer recording medium composed of a support, a thermofusible ink layer formed thereon, which contains as the main components a thermofusible material and a coloring agent, and a resin layer formed on the thermofusible ink layer, which has a structure with minute craters thereon.
    Type: Grant
    Filed: October 21, 1993
    Date of Patent: April 25, 1995
    Assignee: Ricoh Company, Ltd.
    Inventors: Yoshihiko Hiyoshi, Yohji Ide, Keiichi Shiokawa, Masahiro Sato
  • Patent number: 5336548
    Abstract: A multiple-use thermal image transfer recording medium is composed of a heat-resistant support, a thermal image transfer layer formed on the heat-resistant support, which thermal image transfer layer is composed of a plurality of thermofusible ink layers overlaid on the heat-resistant support, and a porous resin layer formed on the thermal image transfer layer. The thermal image transfer layer contains a thermofusible ink component containing as the main components a coloring agent and a thermofusible material. The melt viscosity of the thermofusible ink component in each of the thermofusible ink layers is in such a relationship that the melt viscosity increases toward the heat-resistant support.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: August 9, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiichi Shiokawa, Mihoko Akiyama, Yoji Ide, Yoshihiko Hiyoshi, Masahiro Sato, Kumi Surizaki
  • Patent number: 5328747
    Abstract: A thermal image transfer recording medium comprising a support, and a thermofusible ink layer formed thereon, which comprises a resin matrix and a thermofusible ink, with the above resin matrix and the thermofusible ink having a property of repelling each other.
    Type: Grant
    Filed: July 14, 1992
    Date of Patent: July 12, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Youji Ide, Keiichi Shiokawa
  • Patent number: 5324585
    Abstract: An image receiving sheet for use in a thermal image transfer recording system, has an absorption coefficient (Ka) of 0.05 to 0.75 ml/m.sup.2 .multidot.(msec).sup.1/2 with respect to extra pure liquid paraffin at a pressure of 0.1 MPa when measured by the Bristow's Method (J.TAPPI No. 51-87). As such an image receiving sheet, an image receiving sheet having a recording surface with the product of (a) the absorption coefficient (Ka) with respect to the liquid paraffin (extra pure reagent) measured by the Bristow's Method (J.TAPPI No. 51-87) at a pressure of 0.1 MPa and (b) the gradient (fc) of a linear portion of a load curve obtained by a three-dimensional surface roughness analysis being in the range of 0.5 to 6.0 can be used. An image receiving sheet having a recording surface with the amount (V) of an ink transferred to the receiving sheet during 100 msec being in the range of 2.3 to 11.5 ml/m.sup.2 can also be used.
    Type: Grant
    Filed: June 24, 1992
    Date of Patent: June 28, 1994
    Assignee: Ricoh Company, Ltd.
    Inventors: Mihoko Akiyama, Keiichi Shiokawa, Youji Ide
  • Patent number: 5238726
    Abstract: A thermal image transfer recording medium comprising a support, and a thermofusible ink layer formed thereon, which comprises a resin matrix and a thermofusible ink, with the above resin matrix and the thermofusible ink having a property of repelling each other.
    Type: Grant
    Filed: January 22, 1991
    Date of Patent: August 24, 1993
    Assignee: Ricoh Company, Ltd.
    Inventors: Youji Ide, Keiichi Shiokawa
  • Patent number: 5183697
    Abstract: A thermal image transfer recording medium is composed of a support and an ink layer formed thereon which includes (i) a lower thermal image transfer portion located in the vicinity of the support, containing a three-dimensional network structure of a resin with a voidage A and a thermofusible ink which is held within the network structure, and (ii) an upper thermal image transfer portion located on top of the lower thermal image transfer layer portion, containing a fine porous structure of a resin with a voidage B which is smaller than the voidage A of the network structure, and a thermofusible wax component which is held within the porous structure, and the network structure being at least partially connected to both the porous structure and the support.
    Type: Grant
    Filed: May 5, 1992
    Date of Patent: February 2, 1993
    Assignee: Ricoh Company, Ltd.
    Inventors: Youji Ide, Keiichi Shiokawa
  • Patent number: 5134019
    Abstract: A thermal image transfer recording medium comprising a support, and an ink layer formed thereon, consisting essentially of (i) a lower non-porous layer portion located in the vicinity of the support, comprising a first thermofusible ink and a first resin, and (ii) an upper porous layer portion located on top of the lower layer portion, comprising a second thermofusible ink and a second resin having a minute porous structure in which the second thermofusible ink is supported. In this recording medium, the occupation ratio of the second resin in the upper porous layer portion is higher than that of the first resin in the lower layer portion, and the second resin and the support is connected with each other by the first resin.
    Type: Grant
    Filed: April 18, 1990
    Date of Patent: July 28, 1992
    Assignee: Ricoh Company, Ltd.
    Inventors: Keiichi Shiokawa, Youji Ide