An optical memory card can be a secure and durable data storage card, which is read using a laser light. This technology is often applied to an ISO standard ID-1 credit card format, which allows it to be carried easily by the user. An optical memory card may have a storage capacity equivalent to that needed for storing an average size textbook. Currently the total capacity is between 4.0 and 6.0 megabytes, which results in a useable capacity of nearly 2.8 to 4.0 megabytes. This is enough capacity to store digital files with thousands of pages of text, or up to 200 scanned pages.3 Even with this large storage capacity, the process of filling the card with perforated storage holes by the laser encoder will eventually fill up the card and it will have to be replaced.
Optical write once, read many (WORM) recording ensures that files and data stored on optical memory cards are also secure and safe against tampering, deletions or accidental loss. Files and data on the card can be added to or modified, but not deleted as with a Read-Write CD. When files are added or modified, a permanent audit trail of all access and changes is automatically recorded on the optical media. And because it is an optical device, the card is not affected by magnetic or electrostatic fields and can withstand temperatures of up to 212°F. Optical media, however, is subject to surface damage such as scratches and foreign debris.
Optical memory cards use the same technology made popular by audio compact discs and audio-visual CD-ROM products. Users write on the card with a narrowly focused, high intensity laser beam. A low-power light beam is used to read the physical spots or “pits” created during the writing process.
Optical memory cards are the ideal solution for applications requiring low-cost, durable, secure and comprehensive offline data storage and transportation. Thus, this type of card 3
www.frontlinemagazine.com/card-t.htx; Frontline Solutions, Card Technologies, ©Advanstar Communications
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is ideal for record keeping, such as medical files, driving records, or travel histories.4 Optical memory cards can include color thermal printing, a magnetic stripe, an IC chip and customized security formats. These features also make optical memory cards a highly secure identification. ISO/IEC 11693 and 11694 define standards for optical memory cards.
The optical media is encapsulated between transparent, protective layers of polycarbonate plastic. To record data, an optical card drive uses a laser to burn physical spots on the reflective optical media, similar to CD-ROM recording technology, but with the ability to add more data at any time. These spots or small holes burned onto the media create certain patterns that signify the presence or absence of a hole, which in turn indicates a 1 or a 0. The spots are microscopic in size - as small as 2.25 microns. The smallest size spot the human eye can see is about 20 microns.5 Since it utilizes digital technology any type of digital information can be stored on the card
For example, although it is only the size of a consumer credit card, the LaserCard® optical memory card, as well as other brands, have a digital data storage capacity of book-size proportion. This optical card has about 350 times the capacity of the 8kb integrated circuit (IC) chip card. The high storage capacity of the card allows for the addition of other applications as the need arises without interfering with the original data stored on the card. For example, ten independent data areas can be partitioned on the card, with each one holding about 250kb of data. This enables different departments, agencies, or commercial groups to use their own section, independent and secure from other departments, agencies, or groups.6
High-security features inhibit counterfeiting and data tampering and provide controlled access to the rights granted by the card. The card is primarily used as proof that the cardholder or user has formal permissions, privileges, or rights from the card issuer. These cards are used for immigration, visas, pay-per-use systems, ID/access, cargo manifests, motor vehicles, healthcare, and other digital read/write wallet-card applications.7
To use the optical card, it must be inserted into a reader that is similar to a disk drive, where the reading and writing takes place. The card’s read and write device skims over the surface of the medium to read from or write to the card. Although this technology boasts a very fast seek time with high security features, this technology may not yet be suited for public transit applications where the environment is subjected to heavy
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www.ewh.ieee.org/r10/bmbay/news5/SmartCards.htm; Smart Cards 5
www.lasercard.com/tech/wrdata.htm; Writing and Reading Data 6
www.lasercard.com/tech/datastorage.htm; Data Storage Capacity 7
www.globalmanufacture.net/home/news/card.cfm; Drexler Technology Gets Million-Card Order; 8 Million LaserCard Holders in North America, Growing by 300,000 Per Month, Mountain View, California—(Business Wire)—March 22, 2001
Copyright 2004 American Public Transportation Association Page vibration. If it were to be installed into a fare box, the movement of the bus could throw off the movement of the read/write head, causing data errors.