Title:
INFORMATION RECORDING MEDIUM
Document Type and Number:
Japanese Patent JPH0672085
Kind Code:
A
Abstract:
PURPOSE: To prevent rewriting of irreversible data such as a punch hole.
CONSTITUTION: The code parts 11a-11n coded in accordance with the frequency of use are provided at positions corresponding to the frequency of use on a substrate. After a code part is used as many times as the frequency of use, the code part is removed or destroyed. The code parts 11a-11n are recorded by a hologram system and preferably made smaller than a region to be removed or destroyed.
Inventors:
TAKAHASHI TOKUO
Application Number:
JP24868792A
Publication Date:
March 15, 1994
Filing Date:
August 25, 1992
Export Citation:
Assignee:
DAINIPPON PRINTING CO LTD
International Classes:
B42D15/10; G03H1/18; G06K19/06; G06K19/10; G07F7/12; G11B5/80; (IPC1-7): B42D15/10; B42D15/10; G03H1/18; G06K19/06; G06K19/10; G07F7/12; G11B5/80
Attorney, Agent or Firm:
Hisao Kamata