06424492 is referenced by 3 patents.

A data storage disk having a latent illuminance discrimination marker for determining whether the data storage disk is suitable for use in a disk drive. A light source illuminates the marker and the marker emits illuminance, preferably as phosphorescence. A detector detects the emitted illuminance, and a predetermined characteristic of the marker in the frequency domain is determined. The frequency domain response may be either a phase response or an amplitude response, or both. The frequency domain response provides identification of different types or generations of data storage disks or provides a secure keying mechanism for authorized access to proprietary software.

Title
Frequency based cartridge detection system
Application Number
9/556534
Publication Number
6424492 (B1)
Application Date
April 24, 2000
Publication Date
July 23, 2002
Inventor
Fred C Thomas III
Ogden
UT, US
Paul Smith
Salt Lake City
UT, US
Robert D Allgood
Riverdale
UT, US
Agent
Woodcock Washburn
US
Assignee
Iomega Corporation
UT, US
IPC
G11B 19/02
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