Browse Prior Art Database

Magnetic Read/Write Actuator Mechanism

IP.com Disclosure Number: IPCOM000079925D
Original Publication Date: 1973-Sep-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 2 page(s) / 48K

Publishing Venue

IBM

Related People

Larson, CA: AUTHOR

Abstract

This mechanism accurately positions a magnetic recording and reading head 11 on a magnetic disk 13, by a photoelectric locater 15 effective on the actuator arm 17 carrying the head 11.

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Magnetic Read/Write Actuator Mechanism

This mechanism accurately positions a magnetic recording and reading head 11 on a magnetic disk 13, by a photoelectric locater 15 effective on the actuator arm 17 carrying the head 11.

The arm 17 is pivotally mounted by a flexure pivot assembly 19 so as to swing the head 11 across the upper surface of the disk 13.

The flexure 19 comprises strips 19a and 19b of leaf spring material extending in opposite directions between arm 17 and a fixed base 21. Actuator arm 17 is moved, with flexing of the pivot 19, by a current carrying bobbin 23 that extends between the poles of a permanent magnet 25.

The photoelectric locater 15 conprises an opaque feedback plate 27 mounted on arm 17 and having spaced transparent windows 29 in it. A photocell (PC) block 31 is located below the plate 27 and has a plurality of transparent windows 33 in an opaque plate 34 fixed to block 31. Three phototransistors 35a, 35b and 35c are in block 31 and are located on a radial line extending from the pivot 19. Windows 29 and 33 are slightly skewed, so that, as arm 17 is swung about pivot 19, there are interference openings overlying transistors 35a, 35b and 35c. A light. 37 is disposed above the block 31 and plate 27, so that the transistors are turned on in different patterns as the arm 17 swings.

The three transistors provide position information so that the location of the arm 17 can be accurately determined by associated logic. Another track including wi...