公开(公告)号：DE3378435D1

公开(公告)日：1988-12-15

申请号：DE3378435

申请日：1983-07-04

Applicant: IBM

Inventor： FRATER NORMAN KERMIT ,  HOO STANLEY SHU-KU ,  HARLOW MCCONNELL WILLIAM

IPC: G01B7/14 ,  G11B5/60 ,  G11B5/708 ,  G11B21/20 ,  G11B21/21 ,  G11B33/10

Abstract: Intermittent contacts between a flying transducer head and a magnetic record medium are monitored by detecting triboelectric charges generated by such contacts. Different amounts and polarities of triboelectric charge are generated by different materials on the surface of the record medium. … The flight of the head when it is out of contact with the record medium can be monitored by detecting variations in the displacement current generated as the head flies over the record medium.

公开(公告)号：DE2624185A1

公开(公告)日：1977-01-20

申请号：DE2624185

申请日：1976-05-29

Applicant: IBM

Inventor： HOO STANLEY SHU-KU

IPC: H01J17/34 ,  G06F3/02 ,  G06F3/023 ,  G06F3/033 ,  G06F3/038 ,  G06F3/041 ,  G06F3/044 ,  G09G3/28 ,  H03M11/24 ,  G09F9/00

Abstract: 1526034 Co-ordiriate selection in a rectangular matrix INTERNATIONAL BUSINESS MACHINES CORP 22 June 1976 [23 June 1975] 25777/76 Heading G4H The co-ordinates of a selected point in a rectangular matrix of row and column conductors having drive circuitry arranged sequentially to provide electric pulses thereto, are determined by means of a manipulable sensor 40 with an elongated tip 42 having at least three symmetrically arranged coplanar conductive plates 44A, B, C located laterally of the longitudinal axis of the tip, and sensing circuitry comprising at least two differential amplifiers 54, 63 with respective inputs connected to different conductive plates together with detection circuitry 60, 68, 62 which operates when all differential amplifiers simultaneously generate a null output, so that when the tip is held in proximity to a conductor with the plates capacitively coupled thereto the detection circuitry operates when a pulse is provided to this conductor. With the arrangement shown in Fig. 6, only a pulsed conductor lying within the triangle 72 will result in simultaneous outputs from zero detectors 60, 68 to AND gate 62. The output 71 of AND gate 62 is fed to a further gate 82 which is enabled by the output of a threshold detector 78 provided to eliminate false operation by spurious signals. The output 83 of gate 82 is employed as a DETECT signal which stops a scanning counter whose output indicates the required row or column. The columns and rows may be scanned in turn, or they may be scanned in blocks, a "fine" scan then being performed on the block containing the required conductor. The sensor may be actuated by a pressure sensitive microswitch 48, Fig. 11 (not shown). A sensor with four plates is described with reference to Fig. 9 (not shown). It is stated that the present arrangement of plates and associated circuitry provides increased resolution in the determination of a selected pair of co-ordinates. The matrix may be a gas panel, and the arrangement may be used for data input.