Global Patent Index - EP 0837440 A1

EP 0837440 A1 19980422 - A magnetic head for a magnetic display

Title (en)

A magnetic head for a magnetic display

Title (de)

Magnetkopf für ein magnetisches Display

Title (fr)

Tête magnétique pour un panneau d'affichage magnétique

Publication

EP 0837440 A1 19980422 (EN)

Application

EP 97308356 A 19971021

Priority

JP 29799596 A 19961021

Abstract (en)

A magnetic head (30) comprises a yoke (39) having a pnnting face (39a) which faces to a magnetic display sheet (10) and an air gap hole formed in the printing face (39a), a magnetic core (37) whose edge is inserted to the air gap hole for generating a dot-like recording magnetic field by magnetically coupling with the yoke (39), an electromagnetic coil (38) for supplying a magnetic field to the magnetic core (37) based on printing signals. The distribution of the recording magnetic field is optimised and it becomes possible to prevent a printed dot formed on the magnetic display sheet (10) from being hollowed by setting the diameter d of the edge of the magnetic core to be smaller than the diameter D of the air gap hole and to be 0.8 mm or less. Further, a clear and high density printed dot may be obtained on the magnetic display sheet (10) by setting the diameter D of the air gap hole to be 1.4 mm or less. Thus, high quality magnetic printing may be realised by optimising the distribution of the magnetic field to be generated by the magnetic core. <IMAGE>

IPC 1-7

G09F 9/37

IPC 8 full level

G09F 9/37 (2006.01)

CPC (source: EP)

G09F 9/375 (2013.01)

Citation (search report)

  • [DA] EP 0258791 A2 19880309 - PILOT PEN CO LTD [JP] & JP S63259678 A 19881026 - PILOT PEN CO LTD
  • [DA] PATENT ABSTRACTS OF JAPAN vol. 014, no. 389 (P - 1095) 22 August 1990 (1990-08-22)
  • [DA] PATENT ABSTRACTS OF JAPAN vol. 096, no. 002 29 February 1996 (1996-02-29)

Designated contracting state (EPC)

DE FR GB IT

DOCDB simple family (publication)

EP 0837440 A1 19980422; EP 0837440 B1 20000315; DE 69701435 D1 20000420; DE 69701435 T2 20000720; HK 1006647 A1 19990312; JP H10123987 A 19980515

DOCDB simple family (application)

EP 97308356 A 19971021; DE 69701435 T 19971021; HK 98106050 A 19980623; JP 29799596 A 19961021