A super-twisted nematic display (STN) is a type of monochrome

Monochrome

Monochrome describes paintings, drawings, design, or photographs in one color or shades of one color. A monochromatic object or image has colors in shades of limited colors or hues. Images using only shades of grey are called grayscale or black-and-white...

 passive matrix liquid crystal display

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). STN displays provide more contrast than twisted nematic (TN)

Twisted nematic field effect

The twisted nematic effect was a main technology breakthrough that made liquid crystal displays practical. Unlike earlier displays, TN-cells did not require a current to flow for operation and used low operating voltages suitable for use with batteries...

 displays by twisting the molecules from 180 to 270 degrees. STN LCDs require less power and are less expensive to manufacture than TFT LCD

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...

s, another popular type of LCD that has largely superseded STN for mainstream laptop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. However, STN displays typically suffer from lower image quality and slower response time

Response time

In technology, response time is the time a system or functional unit takes to react to a given input.- Data processing :In data processing, the response time perceived by the end user is the interval between the instant at which an operator at a terminal enters a request for a response from a...

 than TFT displays. STN displays are used in some inexpensive mobile phones and informational screens of some digital products. In early 90's they had been used in some portable computers such as Amstrad's PPC512 and PPC640

PPC 512

The Amstrad PPC512 and Amstrad PPC640 were the first portable IBM PC compatible computers made by Amstrad. They were a development of the desktop PC-1512 and PC-1640 models. As portable computers, they contained all the elements necessary to perform computing on the move...

.

CSTN stands for color

Color

Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...

 super-twist nematic, a color form of passive matrix LCD (Liquid Crystal Display) for electronic display screens originally developed by Sharp Electronics. The CSTN uses red

Red

Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...

, green

Green

Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...

 and blue

Blue

Blue is a colour, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 440–490 nm. It is considered one of the additive primary colours. On the HSV Colour Wheel, the complement of blue is yellow; that is, a colour corresponding to an equal...

 filters

Filter (optics)

Optical filters are devices which selectively transmit light of different wavelengths, usually implemented as plane glass or plastic devices in the optical path which are either dyed in the mass or have interference coatings....

 to display color. The original CSTN displays developed in the early 90s suffered from slow response times and ghosting (where text or graphic changes are blurred because the pixel

Pixel

In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....

s cannot turn off and on fast enough). Recent advances in the technology, however, have made CSTN a viable alternative to active matrix

Active-matrix liquid crystal display

An active matrix liquid crystal display is a type of flat panel display, currently the overwhelming choice of notebook computer manufacturers, due to low weight, very good image quality, wide color gamut and response time...

 displays. New CSTN displays offer 100ms response times (for comparison TFT

Thin-film transistor

A thin-film transistor is a special kind of field-effect transistor made by depositing thin films of a semiconductor active layer as well as the dielectric layer and metallic contacts over a supporting substrate. A common substrate is glass, since the primary application of TFTs is in liquid...

 displays offer 8ms or less), a 140 degree viewing angle and high-quality color rivaling TFT displays - all at about half the cost. A newer passive-matrix technology called High-Performance Addressing

High-Performance Addressing

High-Performance Addressing was developed by Hitachi and is an LCD Passive-matrix display technology commonly found on low-end portable computers...

 (HPA) offers even better response times and contrast than CSTN.

Other STN displays

• DSTN can stand for:
  • Double layer STN - An earlier passive matrix LCD technology that used an extra compensating layer to provide a sharper image.
  • Dual Scan
    Dual Scan
    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...
    
     STN - An enhanced STN passive matrix LCD display. The screen is divided into halves, and each half is scanned simultaneously, thereby doubling the number of lines refreshed per second and providing a sharper appearance. DSTN was widely used on earlier laptops. See STN and LCD.
• FRSTN - Fast Response STN
• FSTN - Film compensated STN, Formulated STN or Filtered STN. A passive matrix LCD technology that uses a film compensating layer between the STN display and rear polarizer for added sharpness and contrast. It was used in laptops before the DSTN method became popular.
• FFSTN - Double film super-twist nematic
• MSTN - Monochrome
  Monochrome
  Monochrome describes paintings, drawings, design, or photographs in one color or shades of one color. A monochromatic object or image has colors in shades of limited colors or hues. Images using only shades of grey are called grayscale or black-and-white...
  
   super-twist nematic
• CCSTN - Color
  Color
  Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
  
   Coded Super Twist Nematic. An LCD capable of displaying a limited range of colours, used in some digital organisers and graphic calculators in the 90's