1. K. Takatoh and S. Nakamura, Japanese Patent 3405972 (2003), 3607286 (2004), 3607272 (2004), 3607270 (2004), US Patent 6445434(2002), Korean Patent 405583(2003)
2. The name “VAC Filter” has been registered in Japan. Registration number 4874254 (Toshiba Electronic Engineering)
3. K. Takatoh and S. Nakamura, Japanese Patent 3607286 (2004) This is the patent for the method using secondary LCDs with figures which are visible from the side and invisible from the front, irrespective of the kind of LCDs. So, any methods showing the figures only to the side direction by using the secondary LCD panel invade this patent
4. http://www.toshiba-tde.co.jp/create.htm#shiya
5. http://uk.computers.toshiba-europe.com/Contents/Toshiba_uk/EN/Others/datasheets/TecraM3_VACF_datasheet.pdf.