Sharp and its partner SEL (Semiconductor Energy Laboratory) unveiled what the companies claim to be the world's first prototype of an LCD (liquid crystal display) with an integrated 8bit processor.
Credit card-size computers predicted by 2005
Putting a CPU directly on the glass substrate of an LCD allows the display to double up as a computer, making possible the development of computers and televisions that are thinner than 2mm.
By 2005, Sharp hopes to develop a new breed of mobile display devices based on CGS, such as information terminals that are as thin as a credit card, said Mikio Katayama, general manager of Sharp's mobile-LCD group.
Display makers, including Sharp, have been putting ICs (integrated circuits) on to glass substrates for some time. Until now, that has meant putting driver ICs, which control the display, on the substrate. The advance announced by Sharp and SEL opens the possibility of putting an entire computer on a glass substrate, including a CPU, memory and other chips.
The prototype announced yesterday was produced using Sharp's CGS (continuous grain silicon) technology. Sharp has been working on the development of LCDs that incorporate ICs and CGS since 1998.
CGS maintains atomic-level continuity at the crystal grain boundaries. This allows electrons to travel through the semiconductor 600 times faster than with conventional amorphous silicon, which is currently used to produce most LCDs, and approximately three times faster than low-temperature polysilicon which is an emerging technology in the field.
The CPU used in the prototype screen produced by Sharp is a Zilog Z80 processor that contains 13,000 transistors and was manufactured using a 3-micron process. Zilog first produced the chip in 1976, Sharp said.