公开(公告)号：JPH0689357A

公开(公告)日：1994-03-29

申请号：JP8343993

申请日：1993-04-09

Applicant: BASF AG

Inventor： KURAUDEIUSU KORUMAN ,  ETSUKEHARUTO SHIYUBUAPU ,  GEERUHARUTO ZEERINGU ,  ROORANDO JIYON BUAICHI

IPC: B42D15/10 ,  G06K7/08 ,  G11B5/02

Abstract: PURPOSE: To provide an excellent method and device which can detect and decode the low retentivity ink Printed document. CONSTITUTION: This method detects and decodes the low retentivity ink printed document. formed by using the magnetic ink that substantially consists of the super paramagnetic solid powder suspension and a substance suspended in water or alcohol. The method tunes to an oscillator 2 which oscillates at a frequency between 10kHz and 10MHz, changes the dielectric constant of a magnetic head 1 where a slit 3 is formed in 5 to 1000μm width by a super paramagnetic material that forms the ink printed document, and records the frequency change caused by the said dielectric constant change as the informational document.