Back to results
US 4,072,994 AGranted
Read-after-write head
AssigneesCanon Kabushiki Kaisha, Canon Denshi Kabushiki Kaisha
InventorHideo Takashima
Life of this patent
Estimating the term…
Abstract
There is disclosed a read-after-write head for use in reproducing information immediately after recording, which comprises a recording or writing core and a reproducing or reading core arranged in the head. A dummy core is juxtaposed to the reproducing core, and a winding of some turns is wound on the dummy core in one sense to be connected in series with the winding wound on the reproducing core in another sense. The voltage induced in the reproducing core due to the cross-field is cancelled by the voltage induced in the dummy core, with the result that the cross-field between the recording and reproducing cores is reduced.
Claims33
A read-after-write head comprising:
- a recording core provided with an information write-in winding for writing information and consistency of two tracks;
- a reading core provided with an information read-out winding for reading information and consisting of two tracks;
- first shielding means for magnetically separating said recording core and said reading core;
- means provided on the reading core side with respect to said shield means and respectively at the outside of said two tracks of said reading core for eliminating electric potential induced in said reading core by the cross-field from said recording core;
- and
- a casing for covering said recording core, said reading core, said first shield means and said eliminating means.
3 more elements
A read-after-write head comprising:
- a recording core provided with an information write-in winding for writing information;
- a reading core provided with an information readout winding for reading information.
- first shield means for magnetically separating said recording core and said reading core;
- a dummy core provided on the reading side with respect to said first shield means and separated from said recording core;
- said dummy core being composed of an independent core and a winding connected in series with said information read-out winding and wound in opposite direction with respect thereto, and said dummy and said reading cores being so arranged that the value of Td/Tc is within a range of 0.6 to 0.8 when the shunt constant k defined by an equation Vd/Td = k.sup.. Vc/Tc is approximately 1.4, where Vc and Vd respectively represent the induced voltages generated in said reading core and dummy core by the crossfield from said recording core, and Tc and Td respectively represent the number of turns of windings on said reading core and dummy core, thereby maintaining the induced voltage in said reading core by said cross-field at approximately a minimum value;
- and
- a casing for covering said recording core, said reading core, said first shield means and said dummy core.
4 more elements
A read-after-write head comprising:
- a recording core provided with an information write-in winding for writing information;
- a reading core provided with an information read-out winding for reading information;
- first shield means for magnetically separating said recording core and said reading core;
- and
- a dummy core provided on the reading core side with respect to said first shield means and separated from said reading core;
- said dummy core being composed of a one-legged core of which one open end only is located at the gap side of said reading core and is aligned with the gap plane of said reading core and a winding on said one-legged core connected in series with said information read-out winding and wound in opposite direction with respect thereto.
3 more elements
A read-after-write head comprising:
- a recording core provided with an information write-in winding for writing information;
- a reading core provided with an information read-out winding for reading information;
- first shield means for magnetically separating said recording core and said reading core;
- a dummy core provided on the reading core side with respect to said first shield means and separated from said reading core;
- said dummy core being composed of a one-legged core of which one open end only is located at the gap side of said reading core and is aligned with the gap plane of said reading core and a winding on said one-legged core connected in series with said informtion read-out winding and wound in opposite direction with respect thereto, said dummy and said reading cores being so arranged that the value of Td/Tc is within a range of 0.6 to 0.8 when the shunt constant k defined by an equation Vd/Td = k.multidot. Vc/Tc is approximately 1.4, where Vc and Vd respectively represent the induced voltages generated in said reading core and dummy core by the cross-field from said recording core, and Tc and Td respectively represent the number of turns of windings on said reading core and dummy core, thereby maintaining the induced voltage in said reading core by said cross-field at approximately a minimum value;
- a casing for covering said recording core, said reading core, said first shield means and said dummy core;
- and
- a juxtaposing core provided with a track width smaller than that of said one-legged core and arranged in a juxtaposed relationship with said open end of said one-legged core to form a gap with said open end.
5 more elements
A read-after-write head comprising:
- a recording core provided with an information write-in winding for writing information;
- a reading core provided with an information read-out winding for reading information;
- first shield means for magnetically separating said recording core and said reading core;
- a dummy core provided on the reading core side with respect to said first shield means and separated from said reading core;
- said dummy core being composed of paired cores consisting of a first core and a second core of a track width smaller than that of said first core positioned in a juxtaposed arrangement with juxtaposed faces lying on the gap plane of said reading core and a winding on at least one of said paired cores connected in series with said information read-out winding and wound in opposite direction with respect thereto, said dummy core and said reading core being so arranged that the value of Td/Tc is within a range of 0.6 to 0.8 when the shunt constant k defined by an equation Vd/Td = k.multidot. Vc/Tc is approximately 1.4, where Vc and Vd respectively represent the induced voltages generated in said reading core and dummy core by the cross-field from said reading core, and Tc and Td respectively represent the number of turns of windings on said reading core and dummy core, thereby maintaining the induced voltage in said reading core by said cross-field at approximately a minimum value;
- and
- said recording and reading cores respectively comprising two tracks, and said pair of first and second cores being provided on each outside of two tracks of said reading core.
4 more elements
Dependencies are inferred from the claim text.