Buried servo recording systems and methods
AssigneeInternational Business Machines Corporation
InventorMunro K. Haynes
Life of this patent
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Abstract
A single-gap transducer simultaneously senses recorded control or servo signals and record data signals. A magnetic medium used with this invention is preferably a single layer magnetic medium. The head gap length and pole-tip face length allow different portions of the pole pieces in a magnetic transducer to be utilized during the simultaneous read and record operations. The servo signals are preferably deep and hard recorded into the layer whereas the data signals are preferably pulse width limited and recorded adjacent the surface portion of the magnetic layer.
Claims26
A magnetic recorder having a single gap magnetic transducer adapted to exchange signals with an adjacent magnetic record medium along a record track being scanned by the transducer, said record medium having a hard recorded control signal, said control signal being a narrow-band low-frequency signal,
- the improvement including in combination:
- information-bearing signal write means connected to said transducer and including high pass frequency characteristics for supplying information bearing signals to said transducer for recording same on the adjacent magnetic medium;
- AC bias means connected to said transducer for supplying an AC bias signal thereto simultaneously with said information bearing signal;
- a control signal circuit having low pass frequency characteristics and connected to said transducer for receiving said control signal from said transducer while said write means is supplying said information bearing signals to said transducer;
- and
- means for simultaneously actuating said write means, AC bias means and said control signal circuit.
A magnetic recorder having a single gap magnetic transducer adapted to record and reproduce signals from a juxtaposed magnetic record medium by scanning a record track thereon, the improvement including in combination:
- a control signal read circuit connected to said transducer for receiving signals therefrom in a first frequency domain;
- a data read circuit connected to said transducer for recovering signals therefrom in a second frequency domain different from said first frequency domain in a non-overlapping portion with respect to said first frequency domain;
- a data write circuit connected to said transducer for supplying a signal to be recorded in said second frequency domain;
- an AC bias circuit connected to said transducer for supplying an AC bias signal thereto, said AC bias signal having a frequency above a higher one of the frequencies in either of said frequency domains;
- and
- control means for simultaneously actuating said control signal read circuit, said data write circuit, and said bias circuit to simultaneously record data signals while recovering the control signals from the record medium via said single gap transducer, and having means to simultaneously receive said signals in said first and second frequency domains for detecting same.
A magnetic recorder having a single gap transducer with relatively long pole piece faces as measured along a track being scanned by the transducer adapted to be placed adjacent to and facing a magnetic record medium carrying said scanned track for exchanging signals therewith;
- high frequency circuit means connected to said transducer for supplying high frequency signals thereto for recording on said magnetic medium by generating magnetic flux patterns in said transducer immediately adjacent said single gap;
- and
- low frequency circuit means connected to said transducer for operating with flux paths in said transducer not adjacent to said single gap at least during predetermined times while said high frequency circuit means are supplying said high frequency signals to said transducer.
A method of operating a magnetic transducer having a gap with a predetermined length,
- said transducer having pole pieces abutting said gap with inner portions near to and outer portions remote from said gap, the steps of:
- imposing high frequency magnetic signals on said pole pieces at least in said inner portion for recording such signal on a magnetic medium via said gap;
- and
- simultaneously to said step of imposing magnetic signals, sensing low frequency signals in said outer portion which are remote from said gap and received from said record medium.
A magnetic recorder having a single-gap transducer adapted to scan a magnetic record member;
- the improvement comprising recording means, read circuit means, and AC bias means, all of said means being connected to said single-gap transducer and all said means being simultaneously active for simultaneously transferring signals to and from said transducer.
A digital signal recorder for recording digital information-bearing signals on a magnetic record member while leaving a prerecorded signal, and with an erased portion adjacent a surface facing a recording transducer,
- comprising:
- means for receiving digital information-bearing signals to be recorded, said signals having transitions between plural successive digital signal states,
- high pass filter means connected to said receiving means for differentiating said received signals to supply a train of narrow pulses to be recorded which pulses represent said signal transitions of said received signals,
- means for supplying a substantially single frequency AC bias signal,
- linear signal mixing means connected to said filter means and said supplying means for receiving said pulses and bias signal to linearly combine same into a recording signal,
- said recording transducer positioned in a recording relationship with the record member, having a recording gap length adapted for recording signals in said erased portion immediately adjacent said facing surface and for receiving said recording signal to record same only in said erased portion.
Dependencies are inferred from the claim text.