Sharp Corp developed an LCD panel that has a memory function to maintain the displayed content even after power supply is cut off and exhibited it at FPD International 2008.
The panel came in 14.1-, 6.1-, 2.4- and 1.7-inch sizes. Sharp presented monochrome and 8-color display panels in 14.1- and 6.1-inch sizes, and monochrome and area color display panels in 2.4- and 1.7-inch sizes.
The panels appeared to use a cholesteric LCD material, but the company's staffer refrained from specifying it. He did not reveal the LCD cell structure, or applied voltage and power consumption for saving content in the memory, either. He, however, said that the power consumption for saving data is "relatively large."
Sharp cited electronic inventory tags, restaurant menu and public signage as applications of the LCD panel. In other words, the LCD panel is positioned as a technology to compete with electronic paper.
As for the inventory tag application, Sharp already began a test operation at a supermarket in Osaka, it said. In the test operation, product prices are displayed on a 2.4- or 1.7-inch memory-embedded black-and-white LCD panel mounted on a substrate equipped with a wireless LAN function and a control circuit to change displayed content.
"This technology makes it possible to easily switch product prices all at once for limited time offers in the evening, for example," the staffer said.
The LCD panel's operational temperature ranges from -25 to +55°C. So, its use is limited to indoors at this moment.
"Displayed content becomes distorted at +55°C and higher, while rewriting displayed content becomes difficult at -25°C and lower temperature," the staffer said.
Commenting on pricing, he said, "It is a bit expensive because it uses some materials that are not usually seen in LCDs. However, we can reuse our old-generation manufacturing lines for its production without making any change to them. So, pricing will probably be equivalent to that of general LCD panels when the scale of its volume production grows."