Smart card displays

The concept of having a display on a smart card is not new. For cash or transport cards the display can show how much credit is left on the card and transactions cause the figure to change.

 

However, the concept has so far failed to make much impact in the market place. The displays need to be cheap, and more importantly they need to be robust so that when the card is flexed they do not break. However, traditional displays have also needed their own power source, and putting a battery in the card limits the life of the card and makes it thick and inconvenient to fit in wallets.

Over the past few years however, there has been some trial of displays on smart cards using bistable displays. Bistable displays keep their image even when the power has been turned off. For example, one Japanese card manufacturer used the contactless RF link on a smart card to power the bistable display and change the value shown. When the card is removed from the RF field the display remains the same until next time it used when it can be changed again.

 

However, due to expense and fragility this display has seen little commericialization as yet.

At a recent Flexible Displays and Electronics conference in San Francisco, Deborah Arnold, Visa's vice president of consumer strategies, said that the company has plans to incorporate a display in their VISA cards. This display will feature information such as the current balance, recent purchases and even local exchange rates.

 

Arnold said working prototypes should be functioning in the next 12 months. Her major concern is that the screens need to be made robust enough for everyday use, ideally suiting printed electronic displays which can be deposited onto flexible substrates rather than traditional rigid displays.

 

Printed displays - such as OLEDs, electrophoretic etc - could finally realise the commercial use of displays on cards.