The display guide
This article aims to make users understand the basics of technologies used in displays in TVs, mobiles, laptops, monitors etc... It tries to explain the tech behind each display, without going into unnecessary detail (which is boring for even techies), and at the same time, covering whatever is required. Please understand that a lot of effort has been put into this article and though you may find articles by professionals on other sites which may go deeper into the concepts and may be (will be
) more professionally written and compiled. But my aim is not to match up to those articles, but to an introduction and a comparison in one place, written in simple language using whatever i know about display technology. It should help newer users grasp what they need to know before purchasing a gadget, or just to get to know about this stuff.
So, here goes:
Ever wondered what is so special about the displays in some recent phones coming out with AMOLED/Super AMOLED display?
Is it actually better than a regular TFT display and should you shell out a few extra bucks to buy a phone with AMOLED display as compared to another similar spec phone which comes with TFT display? (like a Samsung Galaxy S vs Nexus S for instance)(i know they have other minor differences too).
Technologies introduced:
(Plasma technology is not described in comparison because it will not be implemented in mobiles and is now getting phased out fast in India. (Read the newspaper today? Plasmas only account for 2% of total sales. Also, it is not a technology many of us encounter a lot in our day-to-day lives. If you guys request, i can add details about Plasma later).
1) LCD/TFT technology (Normal/CCFL-backlight)
'Liquid Crystal Display' (LCD) displays are the most popular display as of today.
They use a liquid crystal solution placed between the backlight (the lighting on the back of the display, used to illuminate the object/image to display on the screen) and the screen (the layer on which we see the image). Liquid crystals have a liquid-like form, but their molecules are arranged in a crystal-like manner. A 'backlight' is required because liquid crystals are not self-illuminating objects ie. they cannot produce light on their own. They just vary the amount of light from the backlight reaching the screen to produce various colours.
(Light consists of VIBGYOR colours: Blocking light of VIBGYO produces pure red image, allowing all light prodcues white image, blocking all produces black image etc...
In another theory, only Red, Green,Blue colours are considered, and blocked and allowed in different amounts to produce various colours)
Electrical charge is passed through these liquid crystals in varying amounts, making these liquid crystals twist in varying amounts. This twisting leads to variation of light reaching the screen, thus producing the required colours at those required places. (Like among RGB, if red and green light are totally blocked, blue light reaches through).
Standard LCD screens use CCFL(cold cathode fluorescent lamp) backlights.(Not getting into too much detail about CCFL)
EXAMPLE where it is used: A regular LCD TV, the display used in mobile phones like SE Xperia X10, HTC HD2 etc... (in most phones actually).
2) AMOLED stands for Active Matrix Organic Light Emitting Diode.
It uses a totally different type of technology from LCDs.
AMOLED is a type of OLED (Organic LED) which use 'organic' (a class of carbon compounds) compounds , to emit light of different colours based on the current passed through them.
Hence, OLED displays do not require a backlight since they themselves provide the illumination.
EXAMPLE where it is used: Samsung phones such as Omnia II, Jet etc.., Nokia phones such as N8.
Super AMOLED is an improved version of AMOLED.
3)LED-backlight LCDs are just normal LCD displays, with the regular CCFL backlights replaced by LEDs. The backlight may either be formed by completely covering the back of the display with LEDs, which is called array-backlight LED or, by using LEDs on the edges of the display to form an edge-backlight. Now you may realise that array-backlight LEDs are more expensive than edge-backlight ones due to obvious reasons. And also, that they are better than the latter because of the finer control of backlighting that you get with them.
Edge-LED-backlight TVs are better than normal LCDs but they are inferior to array-backlight ones because using edge-LEDs may cause ununiform brightness.
EXAMPLE where it is used: Some phones such as Apple iPhone 4, in "LED" TVs.
The tech used in "LED" TVs is just LED-backlight LCD, and not true LED display.
It is called "LED TV" just as a marketing gimmick. (It is easier to say than LED-backlight LCD and makes customers believe that it is some new species of display)
4) Plasma
Plasma is the oldest of the four display technologies discussed here. In a plasma display, a single pixel is subdivided into three sub-pixels: Red, Green and Blue. The intensity of illumination of each sub-pixel can be varied to such an extent that it is possible to display a total of 16 million colours (one out of these 16 million is displayed at a time) on a pixel. A pixel is a small 'pocket' of plasma (a mixture of ions* of gases). There are two electrodes (one + and one -) in each pixel. There is a phosphor coating on each pixel, whose use will be described later. When we want to display a particular colour on a particular pixel, an appropriate amount of current is passed through the two electrodes (by applying a certain voltage across them). This current causes ions of the gas to travel towards the oppositely charged electrode (+ve ions will move towards -ve electrode, and vice versa). They will collide during this movement, producing photons (minute packets of light), which on reaction with the phosphor coating on the piel to produce varying intensities of illumination on the three sub-pixel. These varying intensities of illumination in the three sub-pixels is used to produce different colours.
Plasma displays are cheaper than LCD displays, especially when the size of the display is larger than 40".
*An ion is an atom which has lost or gained one or more electrons and thus, acquired either a net positive or negative charge. Since an electron has negative charge, losing an electron makes the atom become a positive ion, and gaining an electron makes the atom become a negative ion.
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LED is the future of displays, in televisions,mobile phones and all other gadgets using a display. LED displays are better than LCD (TFT) displays in nearly every field,whether it is viewing angle,power consumption,or even slimness.
OLED TVs will be coming soon, but be ready to burn your pocket to get them, because they will cost you a fortune.
Comparison of AMOLED and LCD in different fields
1)Brightness of screen
OLED displays are brighter as compared to LCD displays. The Super AMOLED display developed by Samsung, is know to have achived the highest brightness (as of date), but also tends oversaturate colours. But LED displays perform poorer (generally) then LCD displays in sunlight.
2)Viewing angle
You may find that if you walk around to the sides of your LCD TV,the display becomes less clear and appears as a grey band when very close to 90 degrees,but for OLED displays, the picture remains as clear and vivid at moderate viewing angles and only exhibits the behavior of LCD displays slowly at large angles.
3)Power consumption
LCD screens require a backlight whereas OLED displays operate without a backlight, thus they consume less power as compared to LCD displays and thus a device can run for a larger amount of time on the same battery.
The more blacks an image on the screen has, the lower power an AMOLED display consumes, but this is not the case for LCD screens, whose power consumption while displaying black objects is not reduced by much. But in the case of displaying more whites, the LCD performs better than the OLED, consuming lower power. In general, the overall power consumption depends on what kind of image the screen is displaying. If it has more blacks, OLED wins, else if it has more whites, the LCD wins.
4)Vividness of display and Blacks
You may observe that on LCD displays,blacks do not appear like those in normal life, they are not very dark and in some cases appear more like grey than black. This is because, displaying black in a LCD screen is not simpler than displaying white on it. The liquid crystals still have to be twisted using electric charge to display anything, including a black spot, thus a perfect black is very hard to produce the black, plus in an LCD display always has a CCFL light behind it while it is operating. The twisting of a liquid crystal has to occur to block light from reaching the display end, which does not occur perfectly, thus there is always some light reaching the screen, and hence it cannot be totally dark, whereas for LED-backlight displays, the pixel which is supposed to display black becomes an “off-pixelâ€(that spot turns off) using the controllable backlight LEDs ,so blacks are sharp and very dark.
The case of an OLED is not as same as a LED-backlight LCD here. An OLED display does not have a backlight at all, so blacks in OLED displays are very deep.
Colors on an OLED display are more vivid and pleasant than LCD and OLED displays have superior contrast ratios and lesser response times, thus reducing blur effects.
But the oversaturation of colours in OLED displays may bother a user.
5) Contrast Ratio
You must be aware that contrast ratio and dynamic contrast ratio are two properties considered very important while buying a HDTV or a monitor.
This article will tell you how important these properties really are and how much weightage they should be given while purchasing a HDTV or monitor.
Meaning: To start with, let us define the two terms we are dealing with.
When we say just contrast ratio, it is supposed to mean static contrast ratio. This static contrast ratio is the ratio of the brightness of the brightest white that can be displayed by the display to the darkest black possible when the display is on.
So,
Contrast ratio = (Brightness of brightest white)/(Brightness of darkest black)
Dynamic contrast ratio is the ratio of the brightest white possible on the display, to the darkest black ever possible on the display, INCLUDING the time when the display's backlight in standby mode, and not at the level it normally operates in.
To do this, they put a totally black image on screen, keep the display in 'dynamic' mode if possible and wait till the backlight goes into standby mode, lowering the brightness level by a large amount.
Now you see why the HDTVs have such high dynamic contrast ratios. If the backlight is dimmed so much that it is almost switched off, obviously the screen now has very little brightness as compared to the brightness of the brightest white when it was in normal mode.
In fact, in LED-backlight displays, the dynamic contrast ratio can easily be over 1 million and i will not be surprised if in the future, i happen to come across an OLED TV which claims to have infinite contrast ratio.
But the place where the customer get cheated the most is when the manufacturer labels the dynamic contrast ratio as just contrast ratio.
While this may not seem to do any harm, it does harm to the sincere manufacturer who labels his static contrast ratio as contrast ratio and tells a number closes to the real number, a few thousand perhaps, while the competitor shows a contrast ratio in the range of 1,00,000:1.
This is where you should not be fooled. It is always better to go for a TV or monitor having higher native resolution as compared to another having a lower resolution and higher contrast ratio. If you see a HDTV having resolution 1366×768 (also called 720p or HD ready) in the similar price range as another HDTV having resolution 1920×1080 (also called 1080p of FULL HD), but the two have contrast ratios of 1,00,000:1 and 50,000:1, go for the second one blindfolded. The rise in contrast ratio will hardly mean a thing. But when you see the sharp increase in clarity when the resolution of the signal is cranked up, you will realise instantly which TV is better.
Conclusion(on this topic of contrast ratio):
Dynamic contrast ratio is not a useless factor, but it should certainly not be the deciding factor while purchasing a HDTV or a monitor.
TVs with higher contrast ratios will perform better in the dark (when lights are off). The blacks of a TV with a higher contrast ratio will be darker, and that of a lower contrast ratio will be a dark grey. But the main problem is that the manufacturer is not revealing the real number. He just reveals a number which is of no practical use to the user. If you are finding the price difference between a higher contrast ratio TV and a lower contrast ratio TV more than a few thousand, go for the cheaper one, because the spending the extra cash is not worth it. With the advances in technology, even in the TVs with the lower contrast ratio nowadays(the minimum seems to be tens of thousands to one lately), the picture quality is almost as good as that in TVs with a higher contrast ratios like that of a million to one. I have even seen some lower contrast ratio TVs having darker blacks than higher contrast ratio ones, indicating some tinkering being done with the numbers out in the specifications.
So, spending a lot more cash to buy a higher contrast ratio HDTV, or going for higher contrast ratio over higher resolution, or preferring a smaller size TV with higher contrast ratio as compared to a larger one portrays the ignorance of the buyer and the victory of the cheating manufacturer.
6)Sunlight legibility
This is a debatable category and there is no clear winner here. The Super AMOLED is said to perform better than regular LCDs, though the mobile display currently having best sunlight legibility is Apple's 'Retina' display, used on iPhone 4 (LED-backlight LCD).
7)Cost
AMOLED screens are more expensive than TFT LCD screens,but the difference does not amount to a huge amount considering the small size of displays on mobile phones. But when it comes to large television screens,the cost difference is significant.
8)Lifespan
Lifespan of AMOLED displays is lesser than LCD displays.But with the average rate of replacement and upgrading of gadgets such as mobile phones and televisions being not more than a few years, this is not much of an issue.
In addition, OLED displays have a lower response time (time taken by display to react to a given input).
Sample images for comparison
1. OLED vs LCD (Image source: techpinas.com)
(LCD above, OLED below)
2. OLED(SuperAMOLED, actually) vs LED-backlight LCD (Image source: HDBlog.it)
(LED-backlight LCD above, OLED below. Click to enlarge)
A display comparison of various phones with different displays: (Image source: GSMArena)
At a larger angle:
At a nearly zero degree angle (Facing us):
Display type in each phone used above
LCD : HTC Desire HD, LG Optimus 7, Sony Ericsson X10. Wave II uses an improved version of LCD.
LED-backlight LCD: Apple iPhone 4.
OLED: Samsung Galaxy S (Super AMOLED), Nokia N8, Samsung wave (Super AMOLED), Nokia C6-01.
CONCLUSION
1)OLED displays are better than LCD displays in almost every aspect.They have larger contrast ratios,lesser response times,more vivid colors,darker blacks,lesser power consumption,wider viewing angle,brighter displays, and some more advantages.
In the mobile phone segment, when it comes to the shortcomings, the higher cost of AMOLED displays of mobile phones as compared to TFT screens and shorter shelf life are not deal-breaking issues due to the smaller margin of defeat in these fields.
But the use of OLED displays in commercial TVs will take time and will come at the cost of a much larger hole in your pocket. Hence, OLED displays are more suited to mobile displays for now and is nowhere near replacing LCDs in the TV, monitor segments.
But if you hate the over-saturated colors of an OLED display, you have no other choice, but to opt for an LCD display.
2) LED-backlight LCD displays come in second place, offering some of the benefits such as lower power consumption, better contrast ratios of OLED in LCD displays. They are the next generation of LCD display: an evolution of LCDs, which will capture and probably overtake the regular LCDs over the next decade, once their prices become comparable to regular LCDs. Their performance is between LCDs and OLEDs in most aspects.
3) Regular LCDs are the most widely use displays in the market now. They have taken over from CRT to dominate the TV segment. But the added advantages of the above two displays, especially the lowering costs of LED-backlight displays is eating into the LCD market. The regular LCD is expected to dominate for a few years at least, and then get overtaken by LED-backlight LCDs as its prices drop enough to get affordable to the masses.
Constructive comments will be appreciated. Thank you.
PS: I do not have the resources to take photos to compare a large variety of displays, so i have posted pictures from other sites for comparison.
Thanks to RS4 for editing help
UPDATE : Introduction on Plasma displays added.
This article aims to make users understand the basics of technologies used in displays in TVs, mobiles, laptops, monitors etc... It tries to explain the tech behind each display, without going into unnecessary detail (which is boring for even techies), and at the same time, covering whatever is required. Please understand that a lot of effort has been put into this article and though you may find articles by professionals on other sites which may go deeper into the concepts and may be (will be
) more professionally written and compiled. But my aim is not to match up to those articles, but to an introduction and a comparison in one place, written in simple language using whatever i know about display technology. It should help newer users grasp what they need to know before purchasing a gadget, or just to get to know about this stuff.So, here goes:
Ever wondered what is so special about the displays in some recent phones coming out with AMOLED/Super AMOLED display?
Is it actually better than a regular TFT display and should you shell out a few extra bucks to buy a phone with AMOLED display as compared to another similar spec phone which comes with TFT display? (like a Samsung Galaxy S vs Nexus S for instance)(i know they have other minor differences too).
Technologies introduced:
(Plasma technology is not described in comparison because it will not be implemented in mobiles and is now getting phased out fast in India. (Read the newspaper today? Plasmas only account for 2% of total sales. Also, it is not a technology many of us encounter a lot in our day-to-day lives. If you guys request, i can add details about Plasma later).
1) LCD/TFT technology (Normal/CCFL-backlight)
'Liquid Crystal Display' (LCD) displays are the most popular display as of today.
They use a liquid crystal solution placed between the backlight (the lighting on the back of the display, used to illuminate the object/image to display on the screen) and the screen (the layer on which we see the image). Liquid crystals have a liquid-like form, but their molecules are arranged in a crystal-like manner. A 'backlight' is required because liquid crystals are not self-illuminating objects ie. they cannot produce light on their own. They just vary the amount of light from the backlight reaching the screen to produce various colours.
(Light consists of VIBGYOR colours: Blocking light of VIBGYO produces pure red image, allowing all light prodcues white image, blocking all produces black image etc...
In another theory, only Red, Green,Blue colours are considered, and blocked and allowed in different amounts to produce various colours)
Electrical charge is passed through these liquid crystals in varying amounts, making these liquid crystals twist in varying amounts. This twisting leads to variation of light reaching the screen, thus producing the required colours at those required places. (Like among RGB, if red and green light are totally blocked, blue light reaches through).
Standard LCD screens use CCFL(cold cathode fluorescent lamp) backlights.(Not getting into too much detail about CCFL)
EXAMPLE where it is used: A regular LCD TV, the display used in mobile phones like SE Xperia X10, HTC HD2 etc... (in most phones actually).
2) AMOLED stands for Active Matrix Organic Light Emitting Diode.
It uses a totally different type of technology from LCDs.
AMOLED is a type of OLED (Organic LED) which use 'organic' (a class of carbon compounds) compounds , to emit light of different colours based on the current passed through them.
Hence, OLED displays do not require a backlight since they themselves provide the illumination.
EXAMPLE where it is used: Samsung phones such as Omnia II, Jet etc.., Nokia phones such as N8.
Super AMOLED is an improved version of AMOLED.
3)LED-backlight LCDs are just normal LCD displays, with the regular CCFL backlights replaced by LEDs. The backlight may either be formed by completely covering the back of the display with LEDs, which is called array-backlight LED or, by using LEDs on the edges of the display to form an edge-backlight. Now you may realise that array-backlight LEDs are more expensive than edge-backlight ones due to obvious reasons. And also, that they are better than the latter because of the finer control of backlighting that you get with them.
Edge-LED-backlight TVs are better than normal LCDs but they are inferior to array-backlight ones because using edge-LEDs may cause ununiform brightness.
EXAMPLE where it is used: Some phones such as Apple iPhone 4, in "LED" TVs.
The tech used in "LED" TVs is just LED-backlight LCD, and not true LED display.
It is called "LED TV" just as a marketing gimmick. (It is easier to say than LED-backlight LCD and makes customers believe that it is some new species of display)
4) Plasma
Plasma is the oldest of the four display technologies discussed here. In a plasma display, a single pixel is subdivided into three sub-pixels: Red, Green and Blue. The intensity of illumination of each sub-pixel can be varied to such an extent that it is possible to display a total of 16 million colours (one out of these 16 million is displayed at a time) on a pixel. A pixel is a small 'pocket' of plasma (a mixture of ions* of gases). There are two electrodes (one + and one -) in each pixel. There is a phosphor coating on each pixel, whose use will be described later. When we want to display a particular colour on a particular pixel, an appropriate amount of current is passed through the two electrodes (by applying a certain voltage across them). This current causes ions of the gas to travel towards the oppositely charged electrode (+ve ions will move towards -ve electrode, and vice versa). They will collide during this movement, producing photons (minute packets of light), which on reaction with the phosphor coating on the piel to produce varying intensities of illumination on the three sub-pixel. These varying intensities of illumination in the three sub-pixels is used to produce different colours.
Plasma displays are cheaper than LCD displays, especially when the size of the display is larger than 40".
*An ion is an atom which has lost or gained one or more electrons and thus, acquired either a net positive or negative charge. Since an electron has negative charge, losing an electron makes the atom become a positive ion, and gaining an electron makes the atom become a negative ion.
-----------------------------------------------------------------------------------
LED is the future of displays, in televisions,mobile phones and all other gadgets using a display. LED displays are better than LCD (TFT) displays in nearly every field,whether it is viewing angle,power consumption,or even slimness.
OLED TVs will be coming soon, but be ready to burn your pocket to get them, because they will cost you a fortune.
Comparison of AMOLED and LCD in different fields
1)Brightness of screen
OLED displays are brighter as compared to LCD displays. The Super AMOLED display developed by Samsung, is know to have achived the highest brightness (as of date), but also tends oversaturate colours. But LED displays perform poorer (generally) then LCD displays in sunlight.
2)Viewing angle
You may find that if you walk around to the sides of your LCD TV,the display becomes less clear and appears as a grey band when very close to 90 degrees,but for OLED displays, the picture remains as clear and vivid at moderate viewing angles and only exhibits the behavior of LCD displays slowly at large angles.
3)Power consumption
LCD screens require a backlight whereas OLED displays operate without a backlight, thus they consume less power as compared to LCD displays and thus a device can run for a larger amount of time on the same battery.
The more blacks an image on the screen has, the lower power an AMOLED display consumes, but this is not the case for LCD screens, whose power consumption while displaying black objects is not reduced by much. But in the case of displaying more whites, the LCD performs better than the OLED, consuming lower power. In general, the overall power consumption depends on what kind of image the screen is displaying. If it has more blacks, OLED wins, else if it has more whites, the LCD wins.
4)Vividness of display and Blacks
You may observe that on LCD displays,blacks do not appear like those in normal life, they are not very dark and in some cases appear more like grey than black. This is because, displaying black in a LCD screen is not simpler than displaying white on it. The liquid crystals still have to be twisted using electric charge to display anything, including a black spot, thus a perfect black is very hard to produce the black, plus in an LCD display always has a CCFL light behind it while it is operating. The twisting of a liquid crystal has to occur to block light from reaching the display end, which does not occur perfectly, thus there is always some light reaching the screen, and hence it cannot be totally dark, whereas for LED-backlight displays, the pixel which is supposed to display black becomes an “off-pixelâ€(that spot turns off) using the controllable backlight LEDs ,so blacks are sharp and very dark.
The case of an OLED is not as same as a LED-backlight LCD here. An OLED display does not have a backlight at all, so blacks in OLED displays are very deep.
Colors on an OLED display are more vivid and pleasant than LCD and OLED displays have superior contrast ratios and lesser response times, thus reducing blur effects.
But the oversaturation of colours in OLED displays may bother a user.
5) Contrast Ratio
You must be aware that contrast ratio and dynamic contrast ratio are two properties considered very important while buying a HDTV or a monitor.
This article will tell you how important these properties really are and how much weightage they should be given while purchasing a HDTV or monitor.
Meaning: To start with, let us define the two terms we are dealing with.
When we say just contrast ratio, it is supposed to mean static contrast ratio. This static contrast ratio is the ratio of the brightness of the brightest white that can be displayed by the display to the darkest black possible when the display is on.
So,
Contrast ratio = (Brightness of brightest white)/(Brightness of darkest black)
Dynamic contrast ratio is the ratio of the brightest white possible on the display, to the darkest black ever possible on the display, INCLUDING the time when the display's backlight in standby mode, and not at the level it normally operates in.
To do this, they put a totally black image on screen, keep the display in 'dynamic' mode if possible and wait till the backlight goes into standby mode, lowering the brightness level by a large amount.
Now you see why the HDTVs have such high dynamic contrast ratios. If the backlight is dimmed so much that it is almost switched off, obviously the screen now has very little brightness as compared to the brightness of the brightest white when it was in normal mode.
In fact, in LED-backlight displays, the dynamic contrast ratio can easily be over 1 million and i will not be surprised if in the future, i happen to come across an OLED TV which claims to have infinite contrast ratio.
But the place where the customer get cheated the most is when the manufacturer labels the dynamic contrast ratio as just contrast ratio.
While this may not seem to do any harm, it does harm to the sincere manufacturer who labels his static contrast ratio as contrast ratio and tells a number closes to the real number, a few thousand perhaps, while the competitor shows a contrast ratio in the range of 1,00,000:1.
This is where you should not be fooled. It is always better to go for a TV or monitor having higher native resolution as compared to another having a lower resolution and higher contrast ratio. If you see a HDTV having resolution 1366×768 (also called 720p or HD ready) in the similar price range as another HDTV having resolution 1920×1080 (also called 1080p of FULL HD), but the two have contrast ratios of 1,00,000:1 and 50,000:1, go for the second one blindfolded. The rise in contrast ratio will hardly mean a thing. But when you see the sharp increase in clarity when the resolution of the signal is cranked up, you will realise instantly which TV is better.
Conclusion(on this topic of contrast ratio):
Dynamic contrast ratio is not a useless factor, but it should certainly not be the deciding factor while purchasing a HDTV or a monitor.
TVs with higher contrast ratios will perform better in the dark (when lights are off). The blacks of a TV with a higher contrast ratio will be darker, and that of a lower contrast ratio will be a dark grey. But the main problem is that the manufacturer is not revealing the real number. He just reveals a number which is of no practical use to the user. If you are finding the price difference between a higher contrast ratio TV and a lower contrast ratio TV more than a few thousand, go for the cheaper one, because the spending the extra cash is not worth it. With the advances in technology, even in the TVs with the lower contrast ratio nowadays(the minimum seems to be tens of thousands to one lately), the picture quality is almost as good as that in TVs with a higher contrast ratios like that of a million to one. I have even seen some lower contrast ratio TVs having darker blacks than higher contrast ratio ones, indicating some tinkering being done with the numbers out in the specifications.
So, spending a lot more cash to buy a higher contrast ratio HDTV, or going for higher contrast ratio over higher resolution, or preferring a smaller size TV with higher contrast ratio as compared to a larger one portrays the ignorance of the buyer and the victory of the cheating manufacturer.
6)Sunlight legibility
This is a debatable category and there is no clear winner here. The Super AMOLED is said to perform better than regular LCDs, though the mobile display currently having best sunlight legibility is Apple's 'Retina' display, used on iPhone 4 (LED-backlight LCD).
7)Cost
AMOLED screens are more expensive than TFT LCD screens,but the difference does not amount to a huge amount considering the small size of displays on mobile phones. But when it comes to large television screens,the cost difference is significant.
8)Lifespan
Lifespan of AMOLED displays is lesser than LCD displays.But with the average rate of replacement and upgrading of gadgets such as mobile phones and televisions being not more than a few years, this is not much of an issue.
In addition, OLED displays have a lower response time (time taken by display to react to a given input).
Sample images for comparison
1. OLED vs LCD (Image source: techpinas.com)
(LCD above, OLED below)
2. OLED(SuperAMOLED, actually) vs LED-backlight LCD (Image source: HDBlog.it)
(LED-backlight LCD above, OLED below. Click to enlarge)
A display comparison of various phones with different displays: (Image source: GSMArena)
At a larger angle:
At a nearly zero degree angle (Facing us):
Display type in each phone used above
LCD : HTC Desire HD, LG Optimus 7, Sony Ericsson X10. Wave II uses an improved version of LCD.
LED-backlight LCD: Apple iPhone 4.
OLED: Samsung Galaxy S (Super AMOLED), Nokia N8, Samsung wave (Super AMOLED), Nokia C6-01.
CONCLUSION
1)OLED displays are better than LCD displays in almost every aspect.They have larger contrast ratios,lesser response times,more vivid colors,darker blacks,lesser power consumption,wider viewing angle,brighter displays, and some more advantages.
In the mobile phone segment, when it comes to the shortcomings, the higher cost of AMOLED displays of mobile phones as compared to TFT screens and shorter shelf life are not deal-breaking issues due to the smaller margin of defeat in these fields.
But the use of OLED displays in commercial TVs will take time and will come at the cost of a much larger hole in your pocket. Hence, OLED displays are more suited to mobile displays for now and is nowhere near replacing LCDs in the TV, monitor segments.
But if you hate the over-saturated colors of an OLED display, you have no other choice, but to opt for an LCD display.
2) LED-backlight LCD displays come in second place, offering some of the benefits such as lower power consumption, better contrast ratios of OLED in LCD displays. They are the next generation of LCD display: an evolution of LCDs, which will capture and probably overtake the regular LCDs over the next decade, once their prices become comparable to regular LCDs. Their performance is between LCDs and OLEDs in most aspects.
3) Regular LCDs are the most widely use displays in the market now. They have taken over from CRT to dominate the TV segment. But the added advantages of the above two displays, especially the lowering costs of LED-backlight displays is eating into the LCD market. The regular LCD is expected to dominate for a few years at least, and then get overtaken by LED-backlight LCDs as its prices drop enough to get affordable to the masses.
Constructive comments will be appreciated. Thank you.
PS: I do not have the resources to take photos to compare a large variety of displays, so i have posted pictures from other sites for comparison.
Thanks to RS4 for editing help
UPDATE : Introduction on Plasma displays added.
