Toshiba Develops Reflective Low-Temperature Polysilicon LCD Technology
Staff -- Semiconductor International, 7/1/1998
Toshiba Develops Reflective Low-Temperature Polysilicon LCD Technology
Toshiba Corp. of Japan (Tokyo, Japan) developed a prototype of a reflective low-temperature polysilicon thin film transistor (TFT) liquid crystal display (LCD). This combination of reflective and low-temperature polysilicon technologies is said to offer low power consumption, increased mechanical reliability and high-resolution (800x600 pixels) in a thin and lightweight package. According to the company, the reflective TFT LCD consumes one-fourth the power, is one-third the thickness and one-half the weight of typical amorphous-silicon backlit TFT LCDs.
The low-temperature polysilicon technology uses a glass substrate capable of achieving higher electron mobility than the amorphous-silicon substrate typically found in active matrix and other LCDs. This allows peripheral driver circuits to be integrated directly onto the substrate, eliminating the need for external mounting of driver ICs around the display panel. For example, one of the company's 1024x768 displays has approximately 280 internal components and more than 4000 internal connections. The low-temperature polysilicon technology reduces component count to less than 200 and reduces the number of internal connections to 200. This also allows a smaller pixel pitch, since no room has to be made for external driver connections.
The company is now planning to start production of a 8.4 in. SVGA (800x600) version of the display in the first quarter of 1999. There are also plans for a 8.4 in. transmissive version with a backlighting system. Plans to offer a 13.3 in. transmissive display with a 1024x768 resolution in limited production quantities also exist, although a high-volume production schedule is still to be determined.
