Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Bidirectional Magnetic Head

IP.com Disclosure Number: IPCOM000076289D
Original Publication Date: 1972-Feb-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Chow, TK: AUTHOR [+2]

Abstract

A double radius magnetic read/write head contour with unsymmetrical gap locations provides, over a wide range of tape velocities: (1) optimum bidirectional operation for read, (2) optimum unidirectional operation for write, (3) a minimum total wrap angle (read wrap angle plus write wrap angle) to minimize wear and tape stick, and (4) amplitude stability.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 2

Bidirectional Magnetic Head

A double radius magnetic read/write head contour with unsymmetrical gap locations provides, over a wide range of tape velocities: (1) optimum bidirectional operation for read, (2) optimum unidirectional operation for write, (3) a minimum total wrap angle (read wrap angle plus write wrap angle) to minimize wear and tape stick, and (4) amplitude stability.

Relative movement of a magnetic tape and the surface of a magnetic read/write head is subject to the principles governing self-acting foil bearings. A hydrodynamically air-lubricated magnetic tape foil flying at constant velocity and tension over a head surface maintains a uniform height over a portion of the head surface. In other regions, the tape height (tape-to-head separation) varies and a point of minimum tape-to-head separation known as "tape dip" occurs. Analysis shows that, for increasing tape velocity, the point of minimum tape-to- head separation ("biggest" tape dip) increasingly shifts downstream from the midpoint of tape tangency (center-of-wrap).

The tape-to-head separation is an important factor in a head's performance, because the electrical effectiveness of the gaps depends upon their proximity to the tape. This becomes especially critical, where a single head is used for reading tape moving in either of two directions and writing in one, or both, of the directions. The tape height over a gap will be different for each direction, and since the read and write gaps canno...