Toshiba Corp. said Friday it has developed a filter that makes the liquid crystal display screens of personal computers and mobile phones visible only to users.
The electronically controlled filter will help ensure privacy and can also be used for electronic voting and automated teller machines, it said.
The filter, itself an LCD, aligns pixels to project a reticulate pattern toward anyone peeping at a screen from the side, Toshiba said.
The direction of the molecules inside the filter -- attached to the surface of a conventional LCD -- can be adjusted by changing the voltage in a small circuit inside a display controller.
Conventional technologies for blocking viewing from the side have involved pasting filters on LCDs. But these filters have also affected head-on viewing.
The new filter technology allows a user to choose between blocking and allowing the viewing of images on LCDs.
Toshiba said it plans to ship electronics products equipped with the new filter in the latter half of fiscal 2004.