Smartphone screens are getting larger, although vendors will likely continue to offer many sizes to woo a wide variety of users.
Today's popular iPhone 4S touchscreen is 3.5 in. diagonally, putting it on the smaller end of today's smartphone screens. In fact, the iPhone screen has remained at 3.5 in. since it debuted in 2007.
In comparison, Samsung's Galaxy S II smartphone, one of the biggest challengers to the iPhone, is 4.3 in., and the Samsung Galaxy Nexus is 4.6 in. The new HTC One X, which will go on sale through AT&T on Sunday, is 4.7 in.
A report surfaced in the South Korean Maeil business newspaper in March that the next iPhone screen would be 4.6 in. (A larger screen also uses more battery power, as Forbes noted.) Meanwhile, MacRumors said a 4.6-in. iPhone 5 is "questionable," but it noted that other sources have concluded it will have a 4 in. screen, still much larger than the screen on the iPhone 4S.
One commenter, identified as Ted, in the U.K.'s Dailymail.com, asked of the rumored larger iPhone: "Will a rucksack be provided to carry it about?"
Still, even a 4.6-in. touchscreen is puny when compared to the Samsung Galaxy Note's 5.3-in. screen -- the biggest screen on any smartphone. Lately, Samsung has begun running TV ads that call the Note more of a smartphone-tablet combination than a smartphone, partly because it comes with a digital stylus that can be used for handwriting and drawing.
On Tuesday, Research In Motion unveiled a prototype BlackBerry 10 smartphone called the Dev Alpha that features a 4.2-in. touchscreen with virtual keyboard. The public won't be able to buy it (it was given away to developers who will build apps for the new BlackBerry mobile OS), and RIM took pains to say that the BlackBerry 10 device to be launched later in the year is likely to be significantly different.
But if RIM is hoping developers begin building apps for BlackBerry 10 on the Dev Alpha, the developers will probably want the screen size to stay at 4.2 in. so the apps they build will render optimally, analysts said. A 4.2-in. BlackBerry screen would be large by RIM's standards.
Screen size is a big factor for users, and it might be the first detail some consider when making a purchase, analysts and manufacturers noted. Screen size alone won't be what persuades a person to buy a certain smartphone, but customers automatically recognize when a phone with a certain size screen is too large or too small to meet their needs.
A larger screen can also mean larger virtual keys for typing, which is important to people with big fingers and hands, manufacturers have said. However, if a user types with one thumb, while holding the phone one-handed (as RIM demonstrated with the Dev Alpha), then the device can't be too large, or the user wouldn't be able reach to the opposite side of the screen with his thumb.
The popularity of multimedia and gaming apps is driving the move to larger screens, analysts said. Larger screens show movies and photos better, but unless the resolution is higher in the larger screens, video quality may not scale. Innovations like Active-Matrix Organic LED (AMOLED), used in the Note and other devices, and the retina display in the iPhone 4S, add to the image clarity.
Given everything that smartphone designers take into consideration when picking a screen size, it's fair to ask if one size is considered ideal, or is likely to sell better than another size. Apple, for instance, has stuck with its 3.5-in. screen on all iPhone models thus far, and it has done phenomenally well with it.
"There is no one ideal size," said Jack Gold, an analyst at J.Gold Associates. "Screen size is about personal preference, just like TV screen sizes or LCD monitors for PCs."
Apple has probably been able to keep down the iPhone's cost of materials by sticking with one screen size, because it can buy the 3.5-in. screens in large volumes, Gold noted. Materials costs "are not a trivial issue for vendors trying to hit a price target," he added.
Over the past year, smartphone screen size has provoked debate on Web forums and in blog comments.
Dustin Curtis posted a blog last year noting that a bigger screen isn't always better. He compared the larger Galaxy S II with the iPhone, explaining that one-handed use of the iPhone is much easier because you can "touch any area of the screen while holding the phone in one hand, with your thumb."
His blog received some derisive comments including: "Since I have two hands, I'll buy a Galaxy," wrote someone identified as Jonny D. Another commenter, Phil Lau, said Curtis has small hands or short thumbs, and chided him for thinking "everyone else has equally short thumbs."
There are also those who say smartphones shouldn't get any bigger. When the Galaxy Note, with its 5.3-in. screen, emerged in February, reviewer Zach Epstein at BGR said: "Samsung basically just 'Samsunged' itself." He concluded: "My sincere hope is that this is the turning point in the giant smartphone trend and we will now see smartphones shrink back down to manageable sizes.... Smartphones like the Galaxy Note and LG Vu have taken things too far."
Matt Hamblen covers mobile and wireless, smartphones and other handhelds, and wireless networking for Computerworld. Follow Matt on Twitter at @matthamblen, or subscribe to Matt's RSS feed. His email address is email@example.com.