公开(公告)号：DE69111100D1

公开(公告)日：1995-08-17

申请号：DE69111100

申请日：1991-03-01

Applicant: IBM

Inventor： BELSER KARL ARNOLD ,  WHITEFIELD RODNEY JOE

IPC: G11B21/21 ,  G11B5/55 ,  G11B5/596 ,  G11B5/78 ,  G11B5/82 ,  G11B21/10 ,  G11B27/19

Abstract: Storage capacity of a magnetic recording medium is increased by providing a nonconductive layer 11 over a magnetic layer 12 on which magnetic data 17 is writable in a series of recording tracks 17, and applying a pattern of electrostatic charges 21 to the nonconductive layer above at least one of the recording tracks 26 to write track-position-denoting servo information in overlying relation to magnetic data. The pattern may be applied by electrostatic charges selectively of negative or positive polarity that are imprinted while the medium is in a mold or advanced over an electro-photographic charge transfer drum, for thereby preprinting the pattern as a step in fabrication of the medium.

公开(公告)号：DE3061867D1

公开(公告)日：1983-03-17

申请号：DE3061867

申请日：1980-04-25

Applicant: IBM

Inventor： WHITEFIELD RODNEY JOE

IPC: B41J2/44 ,  G02F1/33 ,  G03G15/04

Abstract: The invention relates to an acousto-optically modulated scanning system which includes means (8) for generating a beam of light, light deflecting means (16) intercepting light from said generating apparatus for scanning said raster substantially simultaneously in at least one pair of scan lines for creating said image display, acousto-optical modulating means (12, 14) interposed between said light generating means (8) and said light deflecting means (16) for producing a plurality of individually modulatable scanning beams. The modulating means includes means (12) for propagating a pair of acoustic waves in directions substantially normal to the path of said beam of light but offset by the Bragg angle and also normal with respect to each other, and means (14) for individually modulating each of said waves in accordance with data representative of the image to be displayed.