Tokyo--Toshiba Corporation today announced a breakthrough in the integration of Static Random Access Memory (SRAM) into reflective low-temperature polysilicon TFT LCDs for cellular phones that significantly improves display performance. The company's new integration technology cuts power consumption by the display to half that of current cellular phone LCDs, an advance that considerably extends overall standby time. Toshiba will initially apply the breakthrough to the displays of next-generation cellular phones.

Toshiba's SRAM integration technology embeds multiple SRAM cells with each RGB dot in the LCD array, an approach utilizing the higher electron mobility of polysilicon. The SRAM cells integrated in the LCD can hold one bit of data per RGB, allowing users to view e-mail and other stored data, including eight-color photographs, with no need to access the display's peripheral circuitry or for write to the pixel. As a result, power consumption of the LCD in standby mode is cut by approximately 50%, and overall standby time for cellular phones is raised by 23%, from 350 to 430 hours (voltage: 3.3V, 650mAh).

The market for cellular phones is growing and diversifying. Next generation models will support transmission of high-quality motion pictures and improved sound quality, a development that is moving low power consumption into the spotlight. Toshiba will initially apply its new integration technology to 2.1-inch cell phones displays, and subsequently to larger screen LCDs and mass production of SRAM integrated polysilicon LCDs.

Low-temperature polysilicon TFT LCDs offer the most promising solution for mobile personal equipment of any commercialized display. Their use of crystallized silicon allows electrons to pass transistors with much greater mobility than in amorphous silicon TFT, producing a higher resolution and brighter display. They are also significantly smaller, as the display drive circuits can be formed directly on the display's glass substrate, reducing pin connections by 95%.

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