Differences and Explanations of Plasma, LCD, TFTLCD, OLED and AMOLED

  Below is some information to give you an idea of the different
  types of displays on the market, their advantages, disadvantages
  and some technical information.
  Much of the below has been sourced from other articles from all
  over the web then compiled here for your convenience.

As always any further information or corrections can be submitted here for us to update this article.

Plasma
LCD
TFTLCD
TFT
OLED
AMOLED
LED-backlit LCD

Monitor response times and input lag - this links to another page.

Plasma display:

A plasma display panel is a type of flat panel display often found in large TV displays (32" inches or greater). They have tiny cavities between two panels of glass that hold a mixture of gases. These gases are colorless, odorless, tasteless, and non-flammable under standard conditions and have an extremely low level of reactivity.

The gas in the cells is electrically turned into a plasma which then excites phosphors to emit light.

Plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule. The ability of the positive and negative charges to move somewhat independently makes the plasma electrically conductive so that it responds strongly to electromagnetic fields.

A phosphor is a substance that exhibits the phenomenon of phosphorescence (sustained glowing after exposure to energized particles such as electrons or ultraviolet photons).

Advantages

•     Slim profile
•     Lighter and less bulky than rear-projection displays
•     Achieves better color reproduction than LCDs (68 billion versus 16.7 million colours)
•     Produces deep, true blacks allowing for superior contrast ratios (up to 1:1,000,000)
•     Wider viewing angles than that of an LCD
•     Fast response times.(up to 0.001 milliseconds)

Disadvantages

• Susceptible to Screen burn-in and image retention. Newer models have built-in technologies to prevent this such as pixel shifting, however success varies and extended static image exposure may still result in it occuring.
• Phosphors lose luminosity over time, resulting in gradual decline of absolute image brightness, newer models are less susceptible to this, having lifespans exceeding 60,000 hours.
• Susceptible to "large area flicker"
• Generally do not come in smaller sizes than 32 inches
• Susceptible to reflection glare in bright rooms
• Heavier than LCD due to the requirement of a glass screen to hold the gases
• Damage to the glass screen can be permanent and far more difficult to repair than an LCD
   

LCD :

A liquid crystal display (LCD) is a thin, flat panel used for electronically displaying information.

It is an electronically-modulated optical device made up of any number of pixels filled with liquid crystals and arrayed in front of a light source (backlight) or reflector to produce images in color or monochrome

In color LCDs each individual pixel is divided into three cells, or subpixels, which are colored red, green, and blue, using pigment filters, dye filters and metal oxide filters. Each subpixel can be controlled independently to yield thousands or millions of possible colors for each pixel.

Most LCDs use TFT technology.

Advantages

• Lightweight construction
• Portability
• Can be produced in much larger screen sizes than are practical for CRT displays.
• Low electrical power consumption. this enables it to be used in battery-powered electronic equipment.

Disadvantages

• LCDs produce crisp images only in their native resolution. Attempting to run LCD panels at non-native resolutions usually results in image scaling which may introduce artifacts or distortion lessening image quality.
• Cheaper or older LCDs can have "backlight bleed" where light (usually seen around corners of the screen) leaks out and turns black into gray.
• The use of the backlight may reduce the accurate reproduction of black in older displays. However, as of 2009, the very best LCD TVs that do not use LED backlighting can achieve a dynamic contrast ratio of 150,000:1.
• LCDs typically have longer response times than plasma and CRT displays,. Older displays may show visible ghosting when images rapidly change or have an increased input lag to compensate.
• LCD panels tend to have a limited or preferred viewing angle
• Dead pixels can occur. Research a companies dead pixel policy before making a purchase. Some manufacturers think it is acceptable to ship a display with one or two dead pixels. If a manufacturers stipulates a dead pixel policy  then even if the unit is brand new it may not be fixed under warranty. It is rare for modern displays to ship with or even develop dead pixels, it may however be a concern if you are the victim of that rare occurance.

TFTLCD:

Thin film transistor liquid crystal displays are a variant of liquid crystal displays, they use thin film transistor (TFT) technology to improve image quality. Transistors are embedded within the panel itself, reducing "crosstalk" between pixels and improving image stability.The new AMOLED (Active Matrix OLED) screens also contain a TFT layer.

The most beneficial aspect of TFT technology is a separate transistor for each pixel on the display. As each transistor is small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display. Prior to TFT, passive matrix LCD displays could not keep up with fast moving images resulting in ghosting. TFT LCDs are the most widespread display at present. (2009)

OLED:

An organic light emitting diode (OLED), also light emitting polymer (LEP) and organic electro luminescence (OEL), is any light emitting diode whose emissive electro-luminescent layer is composed of a film of organic compounds. The layer usually contains a polymer substance that allows suitable organic compounds to be deposited. They are deposited in rows and columns onto a flat carrier by a simple "printing" process. The resulting matrix of pixels can emit light of different colors.

Advantages

• OLEDs do not require a backlight to function.
• They have very low power requirements.
• Because there is no need for a backlight, an OLED display can be much thinner than an LCD panel.
• OLEDs can be printed onto any suitable substrate using an inkjet printer or even screen printing technologies they can theoretically have a significantly lower cost than LCDs or plasma displays.
• OLEDs on flexible substrates in the future mayopen the door to new applications such as roll-up displays and displays embedded in fabrics or clothing.
• Because OLED pixels directly emit light a greater range of colors, gamut, brightness, contrastand viewing angle than LCDs is possible.
• OLED pixel colors appear correct and unshifted, even as the viewing angle approaches 90 degrees.
• An "off" OLED element (pixel) produces no light and consumes no power which allows it to show true blacks and save energy.
• OLEDs also have a faster response time than standard LCD screens. The fastest LCDs currently have a 2ms response time, an OLED can have less than a 0.01ms response time.

Disadvantages

• A limited lifetime of the organic materials. Blue OLEDs historically have had a lifetime of around 14,000 hours (five years at 8 hours a day) Technology has been developed to reduce or eliminate this problem.
• The intrusion of water into displays can damage or destroy the organic materials. Therefore, improved sealing processes are important for practical manufacturing and may limit the longevity of flexible displays.

AMOLED

This is an active-matrix OLED (see above). An active-matrix OLED display consists of OLED pixels that have been integrated onto a thin film transistor array to form a matrix of pixels that illuminate light upon electrical activation. (TFT - see TFTLCD above for more info)

Active-matrix OLED displays provide the same performance as OLED displays but they consume significantly less power. The amount of power the display consumes does vary depending on what kind of color it shows and bright colors may under some circumstances consume more power than a normal TFT-LCD. (this is in respect to "per pixel")
 

LED-backlit LCD (televisions and monitors)

An LED-backlit LCD is an LCD TV or monitor that uses LED backlighting rather than the fluorescent lights used in traditional LCDs. LEDs (light emitting diodes) are electroluminescent, electricity passes through a semiconductor and the movement of the electrons lights it up.

With OLED TVs and old CRT displays there is light emanating from each pixel. This is not the case with with standard LCD's. Instead the light source, often just one  fluorescent lamp in the bottom of the screen, is shining up through all of the LCD pixels. As a result it lights up the whole display so when they try to show black it sometimes results in a lighter charcoal colour.

This is part of the reason why LED-backlit displays have been developed.

The LEDs can come in two forms, Dynamic RGB LEDs which are positioned behind the panel, or white Edge-LEDs positioned around the rim of the screen which uses a special diffusion panel to spread the light evenly behind the screen.

Edge-lit displays can be very thin, are up to 40 percent more power-efficient than regular LCDs and can be cheaper than local-dimming displays (displays using dynamic RGB LED backlighting).

RGB Dynamic LED backlighting allows dimming to occur in regions, this creates specific areas of darkness on the screen. As a  result you should experience truer blacks and cleaner whites at much higher dynamic contrast ratios.

Though local dimming can produce deeper black levels, it also potentially creates "blooming",  a slight halo or glow created when brighter areas bleed into darker ones and lighten adjacent black levels. EG: White text on dark backgrounds for subtitles.

This may not even be noticeable on some models as it is very dependent on the implementation of the lighting technology.

Advantages

• Top-of-the-line LED TVs deliver as good a picture as plasma TVs
• Generally have a lower power consumption, LED backlighting is more efficient than standard fluorescent backlighting for LCDs.
• Edge-lit TVs are really thin
• They can produce an image with greater dynamic contrast compared with fluorescent backlit LCD TVs.
• They can offer a wider color gamut than most other available technologies, especially when RGB-LED backlighting is used.
• Less environmental pollution on disposal compared to plasma and CRT displays

Disadvantages

• Possible blooming effect
• Possible loss of fine detail on small white objects displayed on dark backgrounds.
• Can be expensive to purchase
• Off-angle viewing on LCDs remains an issue

Use our custom Google search by clicking the following link to find other relevant reviews or faults associated with the Monitors.
(results are displayed within this site.)

Follow these links to find out the product features or to compare prices.