NEC Launches Transflective TFT Color LCD Module for Mobile Terminals

NEC Corporation has developed a new 3.5-inch (8.9cm) high image quality, transflective-type amorphous silicon thin film transistor (TFT) color liquid crystal display (LCD) module. The new product, (Product code: NL2432HC22-20) complete with driver and backlight system is aimed to meet the growing demand coming from the mobile terminal sector and will be used in such products as personal digital assistants. The 3.5-inch NL2432HC22-20 provides a high quality image display with up to 260,000 colors at a resolution of 240 x 320 pixels, and expands NEC's LCD already substantial product line-up for mobile terminals. The new product, featuring the combined structure of a transflective LCD panel, driver and backlight system, is designed for easy installation into vast number of applications. The transflective LCD panel, based on the appropriate combination of NEC's advanced transmissive and reflective LCD technologies has resulted in well-balanced features for two LCD operation modes. The panel, as a transflective LCD, has a high reflectivity of 20% and a contrast ratio of 30:1 in reflective mode. And in transmissve mode, a high transmissivity of 4% and a comparatively good contrast ratio of 100:1 have been achieved, allowing the module to be used in all lighting conditions. By introducing a backlight system with six light emitting diode (LED) light sources the LCD module realizes a top class minimum thickness of 3.5 mm and the lightest weight of 30 grams. Power consumption to drive the panel is held to 25 milliWatts (mW) including drivers with some peripheral circuits such as gamma control and common electrode signal voltage. The use of TFT switches in the module eliminates cross-talk and makes it suitable for moving picture display applications. Sampling will begin from June 2002 and volume production of up to 50,000 units per month is expected to start from September 2002. TFT LCD display technology is seeing a wide application range in products from desktop monitors to notebook computers and a host of other terminals due to clear advantages such as its small footprint, relatively low power consumption and potential environmental benefits. The conventional transmissive-type TFT LCDs with backlight system used until now, have not always been suitable for use with mobile terminals because of the high power consumption and space requirements needed for the backlight. With a growing market for these mobile terminals, such as personal digital assistants and cellular phones, the solution so far has been reflective-type passive-matrix LCD technology, but this does not produce fast response and is not well suited for color screens. NEC's new 3.5-inch transflective TFT color LCD provides high picture quality ,power and space efficiencies typical of reflective TFT LCD technology and is suitable for use in even poor lighting conditions, which until now has been limited to transmissive LCD technology. From now, NEC, will focus on further fusion of its transmissive and reflective technologies to develop new transflective TFT color LCD displays, offering a line-up that meets the needs of each its customers.