Patents by Inventor Nobuhiro Takigawa

Nobuhiro Takigawa 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: 4740494
    Abstract: This invention relates to a method of recording an image, characterized by superposing a heat-sensitive transfer medium on a plain paper and heating the medium thereby transferring a leuco dye from a leuco dye-containing transfer layer and a developer from a developer-containing transfer layer respectively onto the plain paper to react the leuco dye and the developer, said heat-sensitive transfer medium being prepared by having a transfer layer containing a leuco dye as the main component and a transfer layer containing a developer as the main component respectively applied on a single substrate or two separate substrates.
    Type: Grant
    Filed: November 5, 1984
    Date of Patent: April 26, 1988
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideo Watanabe, Keishi Kubo, Kanzirou Kawasaki, Minoru Hakiri, Nobuhiro Takigawa
  • Patent number: 4622565
    Abstract: A multi-colored image recording method capable of producing in repetition clear multi- and full-colored images having high density on a number of receiving sheets is disclosed, in which a thermosensitive image transfer sheet including four leuco dye layers respectively containing yellow, magenta, cyan and black leuco dyes that can be respectively colored in yellow, magenta, cyan and black, and a color developer layer containing a color developer capable of developing the leuco dyes in the four colors is superimposed on a receiving sheet and heat is applied to the thermosensitive image transfer sheet in accordance with the desired color tone information, whereby the leuco dyes and the color developer are transferred from the image transfer sheet onto the receiving sheet so as to selectively overlap the leuco dyes and the color developer, thereby producing multi-colored images by the coloring reaction therebetween.
    Type: Grant
    Filed: January 30, 1985
    Date of Patent: November 11, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Hideo Watanabe, Kanjiro Kawasaki, Keishi Kubo, Minoru Hakiri, Nobuhiro Takigawa
  • Patent number: 4609928
    Abstract: A thermosensitive image transfer medium consisting of (i) an image transfer sheet having an image transfer layer consisting essentially of a leuco dye, and (ii) an acceptor sheet having an acceptor layer consisting essentially of a color developer which induces color formation in the leuco dye, the color developer being a mixture of a bisphenol derivative of the following formula and a p-hydroxybenzoic acid ester with a melting point of 100.degree. C. or less, and, of the image transfer layer and said acceptor layer, at least one layer containing a porous filler having an oil absorption of 50 ml/100 g or more as measured in accordance with the Japanese Industrial Standard K 5101, ##STR1## wherein X.sup.1 and X.sup.2 each represent a lower alkyl group or halogen, R.sup.1 and R.sup.2 each represent hydrogen or an alkyl group having 1 to 6 carbon atoms, and m and n each represent an integer of 0 through 4.
    Type: Grant
    Filed: December 13, 1983
    Date of Patent: September 2, 1986
    Assignee: Ricoh Company, Ltd.
    Inventors: Keishi Kubo, Nobuhiro Takigawa, Eiichi Kawamura
  • Patent number: 4580152
    Abstract: The present invention is directed towards a method for carrying out heat sensitive transfer which comprises using a transfer sheet having a leuco dye-containing transfer layer and a receiving sheet having a receiving layer containing a bisphenol-system compound and a porous filler whose oil absorption is 50 ml/100 g or more and transferring the transfer sheet against the thermal head in the range of 1/N of the length of a picture dot or more (N denotes the number of specified repetitive use of the transfer sheet) to not more than the length of the picture dot per one picture dot recording.
    Type: Grant
    Filed: October 18, 1984
    Date of Patent: April 1, 1986
    Assignee: Ricoh Co., Ltd.
    Inventors: Nobuhiro Takigawa, Keishi Kubo, Hideo Watanabe, Minoru Hakiri, Kanjirou Kawasaki
  • Patent number: 4562448
    Abstract: A heat-sensitive transfer medium of this invention comprises the combination of a transfer sheet which has on one surface of a substrate a transfer layer consisted essentially of a leuco dye and a binder resin and is provided on its opposite surface with a 0.2-5 .mu.m-thick polyfluorocarbon-containing layer with a receiving sheet which is provided on the substrate with a receiving layer consisting essentially of a developer for the leuco dye and the binder resin, and further comprises adding a porous filler (oil absorption: 50-300 ml/100 g) to the receiving layer and/or the transfer layer.
    Type: Grant
    Filed: October 17, 1984
    Date of Patent: December 31, 1985
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideo Watanabe, Minoru Hakiri, Kanjirou Kawasaki, Keishi Kubo, Nobuhiro Takigawa
  • Patent number: 4538164
    Abstract: This invention relates to a heat-sensitive transfer medium comprising a transfer sheet having a transfer layer containing a leuco dye as the main component and a receiving sheet having a receiving layer containing a developer for said leuco dye as the main component, characterized in that said receiving layer contains porous filler having an oil absorption amount of at least 50 ml/100 g and a phenolic compound expressed by the general formula, ##STR1## wherein R represents an alkylene group and X represents hydrogen or a halogen atom.
    Type: Grant
    Filed: November 28, 1984
    Date of Patent: August 27, 1985
    Assignee: Ricoh Co., Ltd.
    Inventors: Nobuhiro Takigawa, Hideo Watanabe, Kanzirou Kawasaki, Keishi Kubo, Minoru Hakiri, Eiichi Kawamura
  • Patent number: 4529993
    Abstract: The heat sensitive transfer medium according to the present invention is characterized in that it comprises a transfer sheet having a transfer layer consisted essentially of a leuco-dye color former and a receiving sheet having a receiving layer consisted essentially of a developer for said leuco-dye and a binder and that said transfer layer further contains 0.01 to 1 part by weight of polyester resin which has a melting point of 50.degree. to 130.degree. C. and a repetition unit represented by the formula: ##STR1## together with 0.01 to 1 part by weight of a porous filler which has an oil absorption of 50 ml or more/100 g, respectively per part by weight of said leuco-dye.
    Type: Grant
    Filed: June 6, 1984
    Date of Patent: July 16, 1985
    Assignee: Ricoh Co., Ltd.
    Inventors: Hideo Watanabe, Nobuhiro Takigawa, Minoru Hakiri, Kanjirou Kawasaki, Keishi Kubo
  • Patent number: 4500896
    Abstract: A heat-sensitive recording medium including:(a) a transferring sheet which includesa first substrate,a lower layer provided over the first substrate and comprised of a discoloring agent and a solid ink having a first color, andan upper layer provided above the lower layer and containing a leuco-compound capable of coloring in a second color which is different from the first color by reaction with a developer at such a first temperature that at least one of said leuco-compound and said developer can melt but that neither the discoloring agent nor the solid ink can melt, the leuco-compound being incapable of coloring upon contact with the developer in the presence of the discoloring agent at such a second temperature that both of the discoloring agent and the solid ink can melt; and(b) a receiving sheet which includesa second substrate, anda developing layer provided over the second substrate and containing the developer.
    Type: Grant
    Filed: January 24, 1984
    Date of Patent: February 19, 1985
    Assignee: Ricoh Company, Ltd.
    Inventors: Keishi Kubo, Hideo Watanabe, Nobuhiro Takigawa, Minoru Hagiri, Kanjiro Kawasaki