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JPS5538513A - Copying preventing device - Google Patents

Copying preventing device

Info

Publication number
JPS5538513A
JPS5538513A JP11086178A JP11086178A JPS5538513A JP S5538513 A JPS5538513 A JP S5538513A JP 11086178 A JP11086178 A JP 11086178A JP 11086178 A JP11086178 A JP 11086178A JP S5538513 A JPS5538513 A JP S5538513A
Authority
JP
Japan
Prior art keywords
copying
rays
writing
chemical
necessary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP11086178A
Other languages
Japanese (ja)
Inventor
Yoshihiro Yonahara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to JP11086178A priority Critical patent/JPS5538513A/en
Publication of JPS5538513A publication Critical patent/JPS5538513A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
    • G03G21/04—Preventing copies being made of an original
    • G03G21/043—Preventing copies being made of an original by using an original which is not reproducible or only reproducible with a different appearence, e.g. originals with a photochromic layer or a colour background

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)

Abstract

PURPOSE:To prevent copying of confidential documents, drawings, etc. by forming a discoloring layer which discolors through chemical change, etc. when rays more than required illuminance necessary for copying are radiated on the writing surface of required writing paper. CONSTITUTION:A discoloring layer 3 which discolors from transparence to black color through, e.g., chemical change, etc. in proportion to the rays radiated when the rays of more than required illuminance necessary for copying with an electronic copying machine or the like is formed on the writing surface 2 of necessary writing paper 2 such as document or drawing. This coloring layer 3 may be a variable color sheet disposed with high-sensitivity silver compound or may use chemicals provided with such chemical properties. It is possible to cover the material through lamination or the like if it is of sheet form or to beforehand coat on the paper surface if it is liquid-form chemical. In this way, copying of confidential documents or drawings may be prevented.
JP11086178A 1978-09-10 1978-09-10 Copying preventing device Pending JPS5538513A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11086178A JPS5538513A (en) 1978-09-10 1978-09-10 Copying preventing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11086178A JPS5538513A (en) 1978-09-10 1978-09-10 Copying preventing device

Publications (1)

Publication Number Publication Date
JPS5538513A true JPS5538513A (en) 1980-03-18

Family

ID=14546524

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11086178A Pending JPS5538513A (en) 1978-09-10 1978-09-10 Copying preventing device

Country Status (1)

Country Link
JP (1) JPS5538513A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5766845U (en) * 1980-10-07 1982-04-21
JPS608880A (en) * 1983-06-29 1985-01-17 Fuji Xerox Co Ltd Device for preventing copying of confidential document
US4586811A (en) * 1982-04-23 1986-05-06 Ricoh Company, Ltd. Confidential document reproduction prevention method
US5638186A (en) * 1991-12-19 1997-06-10 Ricoh Company Ltd. Multi-function machine for combining and routing image data

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5766845U (en) * 1980-10-07 1982-04-21
JPS6240519Y2 (en) * 1980-10-07 1987-10-16
US4586811A (en) * 1982-04-23 1986-05-06 Ricoh Company, Ltd. Confidential document reproduction prevention method
JPS608880A (en) * 1983-06-29 1985-01-17 Fuji Xerox Co Ltd Device for preventing copying of confidential document
JPH0326838B2 (en) * 1983-06-29 1991-04-12 Fuji Xerox Co Ltd
US5638186A (en) * 1991-12-19 1997-06-10 Ricoh Company Ltd. Multi-function machine for combining and routing image data
US6456402B1 (en) * 1991-12-19 2002-09-24 Ricoh Company, Ltd. Device and method for combining images
US6825946B2 (en) * 1991-12-19 2004-11-30 Ricoh Company, Ltd. Multi-function machine for combining and routing image data and method of operating same
US7099050B2 (en) 1991-12-19 2006-08-29 Ricoh Company, Ltd. Multi-function machine for combining and routing image data and method of operating same
US7221484B2 (en) 1991-12-19 2007-05-22 Ricoh Company, Ltd. Multi-function machine for combining and routing image data and method of operating same

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