(19)
(11) EP 0 404 714 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.05.1991 Bulletin 1991/20

(43) Date of publication A2:
27.12.1990 Bulletin 1990/52

(21) Application number: 90810142.1

(22) Date of filing: 26.02.1990
(51) International Patent Classification (IPC)5: B42D 15/08
(84) Designated Contracting States:
DE FR GB IT

(30) Priority: 14.06.1989 JP 69437/89 U

(71) Applicants:
  • KABUSHIKI KAISHA CHALLENGE FIVE
    Osaka-shi (JP)
  • EVERCOAT KABUSHIKI KAISHA
    Osaka-shi (JP)

(72) Inventors:
  • Shibahara, Kenji, c/o K. K. Challenge Five
    Osaka-shi (JP)
  • Houchin, Norio
    Tsurumi-ku, Osaka-shi (JP)

(74) Representative: Baggiolini, Raimondo Patent Attorneys 
Fiammenghi-Fiammenghi Via San Gottardo 15
CH-6900 Lugano
CH-6900 Lugano (CH)


(56) References cited: : 
   
       


    (54) Two-way communication sheets in the form of double post card, double letter sheet, and the like


    (57) The invention relates to a two-way communication sheet in the form of double post card (1-4), double letter sheet (5-9), or the like for use in communicating under cover written information and the like which should be protected from disclosure. The two-way communication sheet is so arranged that a sheet portion on which information is written is bonded to other sheet portion or portions when the communication sheet is initially forwarded as well as when it is sent in reply, so that the information is prevented from being exposed outside. The communication sheet is quite novel in that it enables information to be communicated in secret condition.






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