Bellevue, WA--Revolutionary methods of data storage using various forms of "mini-disks" seemingly make news every week. All of these methods have one thing in common--moving parts. But most design engineers know that if moving elements can be eliminated, reliability, and shock and vibration resistance go up, while device size goes down. By this time next year, ioptics' Optical Read Only Memory (OROM)--without any rotating media and detector arms--is scheduled to be available. The system, part of whose development is being backed by Microsoft, is now in product-prototype trials, and offers designers such packaging advantages to match performance.
Here's the lowdown on how OROM works: Data is optically prerecorded on a plastic data card, slightly smaller than a business card, in 2D patches. Each card contains nearly 5,000 patches of 32 kbytes each, giving a total of 128 Mbytes of useable storage. The user inserts the card into a reader where it is positioned over an array of low-cost, fast-switching, long-life organic light-emitting diodes (OLEDs), one diode for each patch. To access data, the OLED assigned to a patch is illuminated. This 520- to 600-nm (green to amber) light passes through both the patch (creating an "image" of the data) and a micro-diffractive lens layer on the back of the card, again with one lens per patch. A reflective collector lens in the reader focuses the data image onto a central low-cost complementary metal-oxide silicon (CMOS) image sensor. Reader electronics convert the image to digital data for use in an embedded system, computer, game, or audio system. A portion of the data storage overhead is for error correction should an OLED fail--whose data are then recovered via unique software and illumination features.
Data patches are injection molded into the card, as with CD-ROMs, for high-volume applications. For low volume use, data is light activated onto a one-time recordable photo-polymer layer on the card, which can be added to in multiple recording sessions. With embedded systems applications, users install software by entering a data card, which can be easily replaced to upgrade devices.
OROM's random data-access time is 10 ms, equal to most hard drives, and 10 times as fast as CD-ROM drives, according to ioptics president and CEO Fred Hanson. Because data is read in parallel, not bit by bit, the data transfer rate is 1.6 Mbyte/s. Each data card can hold just under two hours of music, whereas a CD holds 78 min. But one of the most striking OROM characteristics is power consumption of merely 200 mW, and this only upon data access. Hanson adds a CD-ROM consumes 1.5 to 2.0W.
"OROM is extremely suitable for mobile computing," says Mike DeNeffe, director of hand-held products at NEC Computer Systems. Ioptics is looking for the first impact of OROM in the hand-held and mobile device market where power consumption is critical, as is resistance to shock and vibration inherent in the system. The high storage capacity will also add to embedded-systems functionality leading to, for example, detailed maps for GPS systems, accurate voice recognition, and multimedia content.
The idea for OROM came from James Russell, ioptics founder and chief technology officer, who pioneered digital optical data recording in the 1960s that led to the CD-ROM. Fred Hanson says the company sees the technology "driving the market to de facto standardization. Beyond its primary software and content distribution function, OROM will allow designers to rethink the fundamental memory architecture of portable and embedded systems to create devices that are significantly more appealing and functional."
What OROM means to you
- Compact data readers
- Easily upgraded embedded- systems software
- Shock-resistant, fast data access
- Low power drain, and only during access