Transreflective liquid crystal display
Encyclopedia
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 backlight
ing 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, and the display itself may be physically damaged.
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
(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
Display contrast
Contrast in visual perception is the difference in appearance of two or more parts of a field seen simultaneously or successively ....
being constant with illuminance
Illuminance
In photometry, illuminance is the total luminous flux incident on a surface, per unit area. It is a measure of the intensity of the incident light, wavelength-weighted by the luminosity function to correlate with human brightness perception. Similarly, luminous emittance is the luminous flux per...
. Only in dim and dark ambient situations an auxiliary transmissive backlight
Backlight
A backlight is a form of illumination used in liquid crystal displays . As LCDs do not produce light themselves , they need illumination to produce a visible image...
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 backlight
Backlight
A backlight is a form of illumination used in liquid crystal displays . As LCDs do not produce light themselves , they need illumination to produce a visible image...
ing 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, and the display itself may be physically damaged.
Trade names
Display manufacturers label their transflective screens under a variety of trade names:- Boe Hydis: Viewiz
- Motion ComputingMotion ComputingMotion Computing is a developer of slate Tablet PC computers located in Austin, Texas. Motion Computing focuses on vertical markets such as healthcare and government, though they have released home-oriented systems like their M-series which was also sold through Gateway Inc...
: View anywhere - LG Display: Shine-Out
- NEC Displays: ST-NLT
- 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).