Korean panel maker Samsung SDI has begun mass-production of AM-OLED (active matrix organic light-emitting diode) screens for the first time. The technology represents an investment of 477.5 billion won for the company. The two-inch screens will be used in mobile phone products. Capacity is currently 1.5m units a month. This is expected to double in 2008, with screen sizes growing to 7-inches, for portable media players. By 2009 the company says it will be making 30-inch AM-OLED TVs for general use. Unlike LCD, AM-OLED screens do not require a backlight and so can be made much thinner. They also consume approximately 40 per cent less power. The worldwide market for OLED screens is expected to exceed 100 million units by 2011.