DETAIL STUDY ON MOBILE PHONE DISPLAY TYPES

Mobile cell phone screen types

Of the different mobile cell phone screen types, two cell phone screen types dominate, the LCD and AMOLED cell phone screens. In LCD and AMOLED cell phones there are variations like IPS LCD screens and Super AMOLED screens. Comparison of IPS LCD and Super AMOLED screens are given in a chart later on this page. We will now explain what the advantages and disadvantages of IPS LCD and Super AMOLED are as follows:

What is IPS display in mobile phones

IPS stands for In Plane Switching. IPS LCD displays for mobile phones are now considered the top of the range in LCD mobile phone screens. LCD screens are mainly of two types: In-Plane Switching (IPS) and Twisted Nematic (TN) type. IPS is the superior technology because it gives much wider viewing angles and much better color to the phone screen.

The LCD screen does not produce any light of its own but acts like a cinema film. To see what is on the LCD screen a light source called the backlight, has to be placed behind the LCD screen, and when the light source shines through the LCD screen you see the picture or writings on the LCD screen. Since the brightness of the backlight in an IPS LCD display can be adjusted, IPS LCD screens can be made very bright to see outdoors in sunlight

What is AMOLED display in mobile phones

The AMOLED (Active Matrix Organic Light Emitting Diode) mobile phone screen produces its own light using organic chemicals based electroluminescent layer as the light emitting medium. This means that each of the tiny OLED pixels light up on their own when an electric voltage is applied to individual cells and the picture is formed by the thousands of Organic Cells lighting up or not lighting up in the AMOLED phone screen.

IPS LCD screen vs Super AMOLED

Both IPS LCD and Super AMOLED mobile phone screen types have its advantages and disadvantages. We are giving below details of both these screens.

IPS LCD and Super AMOLED which is better
Parameter	Super AMOLED screen Mobile	IPS LCD Mobile Screen
Picture Quality	Super AMOLED screen Mobile Phones tend to have better color, brightness, viewing angle and quick response time to fast moving action scenes	IPS LCD screens also have very good picture quality and only advanced instruments can differentiate between the picture quality of latest LCD and AMOLED screen mobiles
Picture Brightness	Super AMOLED mobile phone screen produces its own light and is limited. AMOLED screen mobile phones are very good indoors, but IPS LCD vs Super AMOLED in sunlight, it is difficult to see an AMOLED phone screen so IPS LCD wins	IPS LCD works with a backlight and the backlight brightness can be adjusted according to the ambient light. LCD screens are very good indoors and is quite legible outdoors even in direct sunlight.
Battery Drain	AMOLED is basically an OLED screen which many experts say has the best picture quality with the least amount of battery drain. OLED pixels produces its own light and since a black pixel is the off state and white is in full power mode, then on a full white screen OLED screen may drain faster but if the majority of the screen is kept blak OLED needs very little power and the battery may last for days.	LCD pixels produce no light of its own, it requires a bright backlight which has to be on at full power all the time to see the screen. There can be local dimming libacklights but smartphones to date do not have it. So battery drain with LCD screen is a problem.
Thickness of Phone	AMOLED screen Mobile phones can be made extremely thin, since the AMOLED screen requires no backlight.	Due to the requirement of a backlight, LCD screen mobile phone tend to be slightly thicker than the AMOLED screen mobile phones

What type of screen does the iPhone-6 and iPhone-6+ have

Apple's iPhones use an LCD screen called Retina Display. The Apple Retina Displays use a special type of LCD phone screen called an IPS LCD display. LCD screens using IPS technology is superior because it gives much wider viewing angles and much better color to the Phone screen. Apple used the term 'Retina Display' to signify the human eye's seeing surface and is supposed to impart the meaning that there is no clearer and sharper screen. At the time of its announcement on the iPhone 4 it had a PPi of 326 one of the highest resolutions with the highest PPi among phone screens.

What type of screen does Samsung Galaxy S6 and Note-4 have

Samsung Galaxy Phones have Super AMOLED screens. The Samsung Galaxy phones have screens as good as, if not better than those made by Apple iPhones. The Samsung Galxy phones have much bigger screens than the Apple iPhones and in terms of Pixel Density PPi both have scaled to over 400 PPi, which is much more than what the human eye can distinguish between - that is the human eye cannot make out the difference between Pixel densities of over about 350 PPi. That is to the human eye a phone screen with a PPi of 500 pixels will look the same as a phone screen with slightly over 350 PPi.

Mirasole display mobile phone

The newest promising technology for mobile phone screens is the Mirasole display for mobile phones. Mirasole Reflective IMOD Display is from Qualcomm, the Company best known for its range Snapdragon Processors at the heart of most smartphones. How does Qualcomm Mirasole display work? Qualcomm Mirasole Display works on the principal of interference of light and is referred to as a Interferometric modulator display or IMOD display. Interference of reflected light can create many colors, like what we see on the surface of a floating soap bubble. To quote from Qualcomm Mirasole website:

" Meeting the needs of the new mobile consumer demands new ways of thinking. Creating a color screen that uses reflected light and something called interferometric modulation. That’s a pretty big idea.
So what is Interferometric Modulation? We all learned in school that light travels in waves, and each color of the spectrum has its own unique wavelength. Our displays create an interference of those wavelengths, so that the color the pixel needs to be is the only hue visible to the human eye.
This concept of light and color interference plays out in our everyday life. For example, oil on water produces a rainbow effect. You’ve seen it in soap bubbles and in nature — in the iridescent colors reflected off the feathers of a peacock or butterfly. But how does this happen, exactly?" .................More at the Qualcomm Mirasole website

Qualcomm's Mirasole Reflective Display IMOD screens overcome a major problem of todays leading mobile phone screen types - the AMOLED and LCD mobile screens. Both the AMOLED and LCD screens have a problem of readability under outdoor sunlight conditions. Mirasole Reflective Display IMOD screens have clear phone screens even in the brightest sunlight. Qualcomm recently showed off their new prototype mobile phone screen measuring 5.1 inches diagonally and with a resolution of 2560 x 1440. The PPi of the Qualcomm Mirasole Reflective Displays is 576 PPi (pixels per inch) one of the highest, if not the highest PPi to date on smartphones. Qualcomm says that the Mirasole Reflective Display IMOD screens for mobile phones is very power efficient and claims a power efficiency of about 6 times that of existing LCD or AMOLED screens. These new screens for mobile phones should be hitting the market sometime in 2015

How to measure mobile cell phone screen size

The screen size of mobile cell phones is given as the diagonal measurement of the phones screen. When the size of a mobile phone is in pixels, then it is the measurement of the phone screen size in pixels of the sides of the phone screen, the width and height of the mobile phone in pixels and is called 'Resolution'.

The diagram of a phone here shows the smartphone screen dimensions in centimeters and inches. The phone screen is in light blue color and the screen size is the diagonal distance from the top or bottom corner to the opposite corner at the bottom or top of the screen

The screen sizes of smartphones are normally published in inches, but in many countries following the metric system, like Europe and India, mobile phone screen sizes are also specified in centimeters. To convert inches into Centimeters multiply the inch value by 2.54 (1 inch =2.54 cms or centimeters). To make screen size in inches from centimeters, divide by 2.54.

 

In the smartphone screen image here, the screen size is marked as 10.2 cms or 4 inches which is the measurement from the bottom left corner to the top right corner. Smartphone screen sizes can be specified in two different ways: one by the screen diagonal measurement in inches and, two: by the pixel count on the two sides of the phone screen, that is the width and height of the phone screen.

The pixel density or PPi of a phone screen depends on phone screen size in inches and the pixel measurement of the phone screen. More on this from our page about smartphone pixel density PPi

Pixel size of smartphone screens, mobile phone screen sizes pixels

The screen pixel size of smartphones is the number of pixels in the x-axis by the number of pixels in the y-axis. In the picture on this page, the mobile smartphone screen size in pixels is 720x1080.

The number of pixels along the 'X' axis or horizontally is shown as 720 pixels and along the 'Y' axis or height is shown as 1080 pixels. This is the orientation of the 'X' and 'Y' axis when the phone is held vertically. When the phone is viewed held horizontally the wider width of phone screen becomes the X-axis and the shorter height of screen becomes the Y-axis, when the smartphone resolution is 1080x720.

More on smartphone screen resolution and pixels are given in our page on 'Resolution'

Smartphone maximum screen size, Common Standard Screen size of smartphones

Common Standard Screen size of smartphones now average between 4 to 5.5 inches. The iPhone 6 and iPhone 6+ have a screen size of 4.7 and 5.5 inches respectively. The New Samsung Galaxy S7 has a screen size of 5.1 inches diagonally and the Samsung Note-5 has diagonal screen size of 5.7 inches. There are also popular phones with 6 inch screen sizes like the Google Nexus 6 and Lumia 1520. The maximum size of a smartphone screen now is 6 inches. Smartphones with over 5.5 inch screens are called 'Phablet' - a cross between a phone and a tablet.

Phone Resolution meaning, Mobile phone screen resolution explained

What is Mobile phone screen resolution? To explain what mobile phone screen resolution is, we will start first by knowing exactly how a picture is formed on a mobile phone screen. The screen of a mobile phone is made up of thousands of tiny dots known as Pixels as shown in the picture here.

 A pixel is the short form of ‘Picture Element’. A Pixel on a mobile phone screen is the smallest element which goes to make the picture. Pixels appear as small squares as shown in the picture here. The more the number of pixels to make a mobile phone picture or wording, the sharper it becomes and makes the smartphone screen more easily readable.

Mobile phone screen size in pixels

The size of a mobile phone screen is either given as an inch measurement or as a pixel measurement. The inch measurement is the diagonal screen size as explained on our page about phone screen size.

Mobile phone screen size in pixels is known as the 'Resolution" and is the pixel measurement of a phone screen. So Resolution of a phone screen is a measure of so many pixels from left to right and from bottom to top of the phone screen. The left to right is the 'x' axis and bottom to top is the 'y' axis. Let us say a smartphone screen size in pixels is 720 pixels from left to right and 1080 pixels from bottom to top, then we say the pixel resolution of this smartphone is 720x1080 pixels. It is common practice to write the left to right 'x' axis figure first.

Most common smartphone screen resolutions, mobile phone screen sizes in pixels

The most common smartphone screen resolution are usually according to the following standards. For smartphones when it is held upright, the X-axis or the horizontal measurement is usually smaller than the vertical Y-axis or the height of the screen. Thus in the following, the 'X' and 'Y' axis are based on computer screen measurements where the width is more than the height, like when a smartphone being held horizontally.

Thus for an HD smartphone held horizontally the resolution is 1920x1080 (the X-axis is wider when the phone is held horizontally) and when held vertically the resolution will be 1080x1920.

Standard mobile phone screen resolutions

These are the Standard mobile Phone Resolutions:

VGA (640×480)

VGA stands for Video Graphics Array (VGA) and has become the universal basic standard for measurement of Screen Resolutions. VGA resolution is 640pixels on X-axis and 480 pixels on Y-axis or 640x480. This was the resolution of the first Computer screen for the IBM PS/2 computer in 1987.

QVGA (320×240)

QVGA stands for Quarter Video Graphics Array. The actual screen width and height are half the VGA screen size, but when multiplied the value of the QVGA becomes quarter of the number of total pixels in a VGA screen. That is why it is called Quarter Video Graphics Array or QVGA

WQVGA (xxx×240)

WQVGA is short form of 'Wide QVGA' and is any display resolution having the same height of 240 pixels as QVGA, but the X-axis width is wider, for example 360x240 (3:2 aspect ratio), or 427x2400 (almost 16:9 aspect ratio)

HVGA (480×320)

HVGA Stands for Half VGA or 480×320 pixels. The half value is in the number of pixels and not the physical size of the screen. VGA screen with 640x480 pixels has307,200 pixels and HVGAwith 480x320 pixels has exactly half the quantity of 153,600 pixels

WVGA (xxx×480)

WVGA stands for Wide VGA where the height is the same as VGA at 480 pixels but the width is wider, for example 720x480 (3:2 aspect ratio), or 854x480 (almost 16:9 aspect ratio)

FWVGA (854x480)

FWVGA stands for Full Wide Video Graphics Array and is a display resolution of 854x480 pixels which is about an aspect ratio of 16:9.

SVGA (800x600)

SVGA stands for 'Super Video Graphics Array' also called Ultra Video Graphics Array or Ultra VGA or UVGA is mostly used in computer screen standards.

Quarter HD or qHD (960×540)

QHD stands for Quarter HD where the sides are half the HD measurements of 1920x1080, that is 960x540 pixels.

XGA (1024x768)

XGA, is the short form of 'Extended Graphics Array' with a display size of 1024x768 pixels and was an IBM display standard of 1990.

WXGA (1366x768)

WXGA is 'Wide Extended Graphics Array' is a modification of XGA with wider screen for example 1366x768 which has an aspect ratio of 16:9.

 HD Phone Screen Resolutions

The following are the different types of High Density HD resolutions that are now becoming common in high end smart phones.

Full HD (1920x1080 pixels)

HD stands for High Definition with a resolution of 1920x1080 and in the wide angle ratio of 16:9.

Hd ready (720x1280)

HD ready is an older standard of High Density screens.

Quad HD (1440x2560)

Quad HD has four times the total number of pixels than 'HD Ready'(720x1280). The sides are double, but when you multiply the two side pixel counts you get 4 times the number of pixels.

Ultra HD 4K (3840x2160 pixels)

Ultra HD stands for Ultra High Definition with a resolution of 3840 x 2160 pixels. Since 3840 pixels horizontally is almost 4000 pixels, it has been named a 4K resolution where 'K' represents 1000. The aspect ratio is 16:9. 4K phones have not yet hit the market, but expect them soon.

Best screen resolution for Phones

The best screen resolution for phone is when the relation between phone screen size and resolution gives a pixel density of about 300 pixels per inch or 300 PPi. Even though the more the value of the PPi the clearer and sharper the phone screen becomes, there is an upper limit for PPi above which the human eye cannot distinguish higher PPis.

Sometimes mobile smartphone resolutions are given as the X and Y axis values like 1500x800 pixels. Without knowing the screen size we cannot have a relation between screen size and resolution to calculate the pixel density or the Pixels Per inch PPi. It is the density of the pixels in a smart phone screen that determines the sharpness and quality of the picture. The same number of pixels in a smaller screen gives much sharper pictures. Thus the highest phone resolution pixel numbers alone does not give you an idea of how good the mobile phone display is, you also need to know the screen size.

The human eye cannot distinguish the difference in PPi when the figure reaches a saturation point of about 300 PPi. So having a PPi of much more than 300ppi will not make the screen that much clearer but there is a penalty for having high PPi, there will be faster battery drain of the phone because more power is required to light up more pixels.

Best Pixel Density Phones 2016
Model	Screen Size Inch	Screen Size Cms	Resolution Pixels	Pixel Density PPi
Samsung Galaxy S7	5.1	12.95	1440 x 2560	571
LG G3	5.5	13.97	1440 x 2560	534
Samsung Galaxy Note 5	5.7	14.48	1440x2560	515
Nexus-6	5.96	15.14	2560 x 1440	493
HTC One M8	5	12.7	1080 x 1920	441
Samsung Galaxy S5	5.1	12.95	1080x1920	432
Sony Xperia Z3	5.2	13.21	1080x1920	424
Moto X	5.2	13.21	1080x1920	424
iPhone-6 Plus	5.5	13.97	1080 x 1920	401
Lumia 1520	6	15.24	1080 x 1920	367
iPhone-6	4.7	11.94	750 x 1334	326