Kent Displays (Kent, OH; www.kentdisplays.com) pioneered the development of bi-stable displays ­- displays that can retain an image without any power applied to the display at all - with several related display technologies culminating in the current cholesteric LCD (ChLCD). Power is required only when the image is changed (or "re-written"). But Kent became involved in a long series of patent and theft-of-trade-secrets suits with arch-rival ADS. Kent won and ADS folded, but the legal fight was a huge strain on the small company. As a result, not much was seen from Kent for several years other than demonstrations of prototypes and low-volume products, such as flexible display that they can be made on clothing.

Ken Werner
Senior Analyst and Editor
of MDTV Retailer

But now, the company has announced an application and a customer that could reach high volumes in the near future. The application is USB flash drives and the customer is Taiwan’s Carry Computer (www.mydidigo.com), a 15-year-old company recently admitted to the Taiwan Stock Exchange. The Didigo USB SmartDrive was introduced at CeBIT in March. The display has an 11-character display area that can be used as a rewritable label to identify the drive, and both a pie chart and 4-digit area to indicate available memory space. Rewriting of the display is done when it’s plugged into the host system and receiving power from the USB port.

If you think such a product is a good idea, Kent and Carry Computer are not the only companies to agree with you. At CES, Lexar announced a similar product, the Lexar JumpDrive Mercury, which contains a simple "fuel gauge" display of available drive capacity. The display is based on E Ink’s (Cambridge, MA; www.eink.com) electrophoretic technology, which is also bi-stable.

And Royal introduced the Royal Vista EZVue Flash Drive with a 2-line scrollable display and a 4-button controller that allows you to view the names of all the files on the drive. No information was provided about the display, but since the display is changing when you scroll it, there has to be a battery on board even if display technology is intrinsically bi-stable.

We tend to concentrate on displays that are large, bright, and colorful - or, in the case of portable devices, small, bright and colorful - but as these three flash drives demonstrate, there are many applications for displays that are small, simple and bi-stable (or extremely energy-efficient). These displays allow users to see inside what was formerly a featureless, uncommunicative box, and to do so at low cost.