LCD that displays on both sides

Mitsubishi Electric has developed a "reversible' liquid crystal display that can display images on both its front and rear surfaces.

The firm says this could provide a lighter, thinner and cheaper alternative to the two separate displays that many folding mobile phones use today.

The reversible LCD makes use of two transparent backlights. This means that it contains only one liquid crystal glass panel, which is sandwiched between the backlights.

Many folding mobile phones have two displays: a large, main display and a smaller sub-display that is used when the handset is folded shut.

As LCD backlights usually have non-transparent white diffusible light guide plates, conventional designs require two separate LCDs to display images on both surfaces.

In contrast, the light guide plates in Mitsubishi's backlights are made up of invisible fine light reflecting prisms which appear transparent when switched off and bright when switched on.

Switching the backlights on or off enables the LCD to display images on its front side, rear side or both at the same time.

The display is said to have a brightness of 150 cd/m2, which is equivalent to that of conventional LCD module designs. Image quality is also said to rival that of conventional module designs.