Browse Prior Art Database

Power Down of Sensors on Removable Media Drives

IP.com Disclosure Number: IPCOM000108569D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 44K

Publishing Venue

IBM

Related People

Goodman, BG: AUTHOR [+2]

Abstract

Sensor life can be extended and sensor error detection can be improved by powering off the drive sensors when not needed.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 76% of the total text.

Power Down of Sensors on Removable Media Drives

       Sensor life can be extended and sensor error detection
can be improved by powering off the drive sensors when not needed.

      Typical light-emitting diode (LED)/photo-detector sensors tend
to degrade and fail as a function of power-on time.  If the sensors
are powered off when not needed, the life and quality of the sensor
signals can be lengthened.

      This power on/off capability also adds another state as well as
a method of controlling the status of the sensors. This allows for
the detection of errors, such as a bad sensor, wrong state of the
mechanism being controlled, etc. This same methodology can also be
used for purely mechanical switches as well.

      The current implementation uses the spindle motor start line to
indicate that all the sensors have been read and are not needed while
the spindle is spinning and are, therefore, powered down.  When the
start line becomes active, the power to the LEDs and photo-detectors
is dropped.  This not only extends the life of the sensors, the LEDs
in particular, but also lowers the power consumption in the drive or
makes more power available to other functions, in the case where the
drive is power supply limited.  This is achievable because the life
of LED/ photo-detector sensors is purely a function of power-on hours
and is virtually unaffected by the number of power on/off cycles.

      Another method is to allow for the drive microcode...