Samsung Develops Double Sided LCD With Independent Display for Mobile Phones

Samsung Electronics announced today that it has created the first LCD panel that can produce independent images on each side (front and back) of a mobile LCD display.

This will replace traditionally used dual display panels with one, thereby reducing overall thickness of mobile products by at least 1mm. It is expected to commence mass production in the first half of 2007.

The LCD product uses of double-gate, thin-film transistor (TFT) architecture. TFT gates are electronic components that convert the necessary voltage at the pixel level, which controls the liquid crystal alignment needed to reproduce on-screen images. Samsung’s new double-sided LCD has two gates that operate each pixel instead of one, so the screen on the front can display different images than the one on the back. The double-sided display makes use of Samsung’s proprietary Amorphous Silicon Gate (ASG) technology, which accommodates the increased number of TFT gates without increasing the size of the driver integrated circuits. Driver-ICs typically increase in size when more TFT gates are used.

The new Samsung mobile display requires only one backlight. One side of the panel operates in a transmissive mode, while the other operates in a reflective mode. By using a unique reflective design that utilizes the light trapped in the opposing screen’s transmissive mode, the reflective mode does not solely rely on external light sources such as the sun.

It is 2.6mm thick and 2.22″ wide, with QVGA (240 x 320 pixel) resolution, and has brightness values of 250 nits for the front and 100 nits (candela per square meter) for the rear display. It will be exhibited at the Consumer Electronics Show at Las Vegas.

Resolution formats for small and mid-sized LCDs:

• qqVGA: 128 pixels horizontal by 160 rows vertical
• qCIF: 176 pixels horizontal by 220 rows vertical
• qVGA: 240 pixels horizontal by 320 rows vertical
• qSVGA: 300 pixels horizontal by 400 rows vertical
• VGA: 480 pixels horizontal by 640 rows vertical

The possibility of a slimmer mobile phone isn’t that exciting to me. It is already as small as a large keychain, anything smaller and it will slip out of my hands. My personal interest in this technology is in the possibility for making slimmer laptops which can be viewed while closed. Imagine that you are on a flight with few choice DVD’s and your laptop. Now you can simply perch your slim laptop (think slimmer than VAIO) like a picture frame on the tray table and enjoy your movie, no more hindered by the clumsy keyboard. I would probably fasten it with a clip over the existing low resolution super-small flat screen provided in most commercial flights today.