What is the difference between a Plasma and an LCD screen?
Everyone seems to want to buy one these days, but what's actually the difference between plasma and LCD screens?
This blog tries to tackle this question...
Based on outward appearances are definitely deceiving when it comes to LCD and Plasma screens. Although both types of screens are flat and thin, they utilise different technology in an attempt to deliver similar results.
These work on a grid system of pixels, illuminated by a backlight that passes through a polarizer. This light is controlled by voltage coursing through crystal liquids that run in between two glass panels. The pixels are etched onto the glass panels, and create the pictures we see on the screen.
They work a bit differently to LCD screens. The plasma screen has a similar grid of pixels. These are controlled in a different manner. Instead of liquid, gasses such as neon and xenon control each individual pixel. Each pixel has a long electrode attached to it. Phosphors in each square are illuminated by electric currents running through the gas in the screen.
When you're comparing plasma and LCD screens, you're actually comparing their two competing technologies. Both technologies achieve similar things (i.e. crystal-clear, colour-filled pictures) and come in similar designs (i.e. super-thin housing). However, there're some key differences:-
1. Screen Size – there are larger plasma screen size available. The minimum plasma screen size is 32”, where as the LCD screens range from 7” up to 108”.
2. Thickness - On average LCD screens are 50mm depth whereas the Plasma is 75mm depth.
3. Viewing Angle – Plasma screens use to have a better viewing angle (up to 160 degrees), but the LCD screens have now exceeded Plasma, and now modern LCD screens have a viewing angle up to 178 degrees.
4. Burn-in - Plasma screens are more susceptible to burn-in of static images. However, this problem has diminished greatly in recent years as a result of the incorporation "pixel orbiting" and related technologies, but still cannot compete with LCD screens.
5. Screen Refresh Rates – Plasma screens have better motion tracking (little or no motion lag in fast moving images), whereas LCD screens were originally designed for computer data displays, and not video. LCD refresh rates have been improved and with rates of 16 ms or higher show very little noticeable difference, but they still suffer from a very slight 'trailer' effect - so plasma screen technology slightly edges it here.
6. Colour Saturation - In plasma screens, each pixel contains red, green, and blue elements, which work in conjunction to create 16.77 million colours. Colour information is more accurately reproduced with plasma screen technology than it is with any other display technology. LCD displays reproduce colours by manipulating light waves and subtracting colours from white light. This makes it more difficult for maintaining colour accuracy and vibrancy. But, LCD screens have colour information benefits from the higher-than-average number of pixels per square inch found in their displays (especially when compared to plasma screens). Plasma screens are better here than LCDs with similar pixel counts and for moving images. LCD screens are better at displaying crisp static images.
7. Contrast Ratios – Plasma screens have a better contrast ratio and measure up to 3000:1 (which is the measure of the blackest black compared to the whitest white). Current LCD screen contrast ratios can measure up to 1000:1. This means, for scenes with a lot of dark and light images shown simultaneously (such as with content originating from DVDs and video games) plasma screens will normally outperform LCD screens. However, this is debatable and many of the best quality LCD screens display sufficiently dark blacks to please even the most discriminating eyes.
8. Product Life-Span - Typically plasma screens have a life span of 25,000 to 30,000 hours, which equates to about 3 years of 24/7 usage before the TV fades to half the original brightness, whereas a LCD screens life span is typically 50,000-60,000 hours. This equates to about 6 years of 24/7 use. However, LCD TVs will actually last as long as its backlight does, and those bulbs can be replaced - so in essence there's nothing which can wear out. LCD screens run about twice as long as Plasma screens. LCD screens are therefore preferred for long-haul applications like 24/7 signage in the retail sector.
9. Weight - Plasma displays are fairly heavy. When mounted on a wall or ceiling, these need to be able to bear the weight and may require additional supports. LCD screens weigh less than similarly sized plasma screens, and can be more easily installed. LCD screens are considerably lighter and as such easier to mount and install. Plasma screens will almost certainly require a professional installer.
10. Transportation and Shipping - Due to their fragile nature, plasma screens need to be shipped by specialty carriers. Overnight or fast delivery options are not recommended. Special shipping methods and their heavier weight might add to higher shipping costs (although most UK retailers don't alter the shipping price). Shipping LCD screens is not difficult, and is not as expensive as shipping plasma displays. LCD displays are lighter and far less fragile than plasma displays making shipping easier.
11. Production Costs and Price - Plasma screens are easier and as such cheaper to produce in large sizes (40” upwards). The substrate material for LCD screens has proved difficult to produce in large sizes (over 32”) without pixel defects owing to faulty transistors. Although prices for both technologies have dropped significantly over the years, plasma screens are still significantly cheaper for sizes over 32”.
12. Power Consumption - Plasma screens are fairly power hungry and use a lot of electricity lighting each and every pixel you see on a screen (even the dark ones), thus generating more heat than LCDs. LCD screens use florescent backlighting to produce images, and as such require substantially less power to operate. LCD screens use on average half of the power from Plasma screens.
13. Performance at High Altitude – High altitudes can affect the performance of plasma screen displays because the gas held inside each pixel is stressed, and has to work harder to perform. This means you may get a buzzing noise, which sounds rather like the humming of an old neon sign. LCD screens are affected by high altitudes.
Hopefully, this blog was useful in explaining the difference between plasma and LCD screens.
When deciding upon LCD or Plasma, your choice will depend on the value you attach to the different features. If you’re after a large screen size at a reasonable price, than plasma screens are your best option. However, depending on the use of your screen, i.e. you're going to leave it on a lot, and want to use it to display computer applications as well, than go for a LCD.
If you have any questions and want to find out more about this, you should call us today on 0845 234 0375