May 24, 2007 – NEC’s LCD display unit has created a LCD module that incorporates all chip components, including LSI and memory, on the glass substrate.
Whereby conventional LCD modules require attaching a separate board with LSI and memory to the glass substrate with built-in driver, NEC’s new module includes a system chip with everything needed to operate the display: a 230Kbit DRAM, 6bit digital-analog converter, picture decoder and encoder, controller, and 400,000 transistors, all fabricated on a polysilicon film on the glass, the Nikkei Business Daily notes.
NEC also boasts other processes to enhance the LCD module, including a proprietary graphical data compression/decompression technology that enables a two-thirds reduction in the amount of memory required to store data from one screen image, and a RGB horizontal stripe (instead of a vertical RGB stripe) to enable high density and optimize the frame memory’s cell layout.
Fabricating all the components directly on the glass not only reduces the number of peripheral chips needed, it also saves time waiting for chipmakers to fabricate the extra system LSIs (cutting normal six-month development times in half), reduces costs, and allows LCD makers to produce a thinner module, the paper noted.
“Embedding the frame memory onto the glass substrate is a completely new breakthrough in system-on-glass LCD technology, and will enable significant reductions in display power consumption,” said Hideki Asada, senior research manager of NEC LCD Technologies.
A 1.1-in. prototype TFT LCD display incorporating the all-in-one elements currently sports 160×120 resolution. A commercial version could be ready in two or three years. NEC’s ultimate goal is a “zero chip display” that would enable direct connection to the system’s MPU bus line.