Dual Scan
Encyclopedia
Dual Scan, also known as dual-scan supertwist nematic or DSTN, is an LCD technology in which a screen is divided into two sections which are simultaneously refreshed giving faster refresh rate than traditional passive matrix screens. It is an improved form of supertwist nematic
display that offers low power consumption but inferior sharpness and brightness compared to TFT screens
. For several years (late '90s to early 2000s), TFT screens were only found in high-end laptop
s due to them being more expensive and lower-end laptops offering DSTN screens only. This was at a time when the screen was often the most expensive component of laptops. The price difference between a laptop with DSTN and one with TFT could easily be $400 or more. However, TFT gradually became cheaper and has essentially captured the entire market.
DSTN display quality is poor compared to TFT, with visible noise, smearing, much lower contrast and slow response. Such screens are unsuitable for viewing movies.
Super-twisted nematic display
A super-twisted nematic display is a type of monochrome passive matrix liquid crystal display . STN displays provide more contrast than twisted nematic displays by twisting the molecules from 180 to 270 degrees...
display that offers low power consumption but inferior sharpness and brightness compared to TFT screens
TFT LCD
Thin film transistor liquid crystal display is a variant of liquid crystal display which uses thin-film transistor technology to improve image quality . TFT LCD is one type of Active matrix LCD, though all LCD-screens are based on TFT active matrix addressing...
. For several years (late '90s to early 2000s), TFT screens were only found in high-end laptop
Laptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
s due to them being more expensive and lower-end laptops offering DSTN screens only. This was at a time when the screen was often the most expensive component of laptops. The price difference between a laptop with DSTN and one with TFT could easily be $400 or more. However, TFT gradually became cheaper and has essentially captured the entire market.
DSTN display quality is poor compared to TFT, with visible noise, smearing, much lower contrast and slow response. Such screens are unsuitable for viewing movies.