Transflective liquid crystal display

A transflective liquid crystal display is a liquid crystal display (LCD) that reflects and transmits light (transflective = transmissive + reflective). Under bright illumination (e.g. when exposed to daylight) the display acts mainly as a reflective display with the contrast being constant with illuminance. Only in dim and dark ambient situations an auxiliary transmissive backlight should be provided. When an illuminance sensor is added for control of the backlight, such a transflective LCD can be read over a wide range of illuminance levels. This is why that technique is often found in automotive instrumentation. In portable electronic devices the transflective mode of operation helps to save battery charge, since in bright environments no backlighting is required.

The essential component for a transflective LCD is the transflector, a polymer sheet that is reflecting and transmitting at the same time.

Some displays which transmit light and have minor reflectivity are best readable in the dark, and fairly readable in bright sunlight, but under a particular angle only, and are least readable in bright daylight without direct sunlight. Under exposure to direct daylight, the image on non-reflective displays will completely wash out.

Trade names

Display manufacturers label their transflective screens under a variety of trade names:

• Boe Hydis: Viewiz
• Motion Computing: View anywhere
• LG Display: Shine-Out
• NEC Displays: ST-NLT
• Pixel Qi: 3Qi
• For a review of this technology: X. Zhu, Z. Ge, T.X. Wu, and S. T. Wu, "Transflective liquid crystal displays," Journal of Display Technology, 1, 15-29 (Sept. 2005).

See also

• Anti-reflective screen

External links

• Close up views of transflective pixel structure