Curved glass is more than a marketing gimmick

Curved glass is more than a marketing gimmick

Summary: A display industry expert thinks that the trend toward curved displays in gadgets has merit. Here's why.

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GalaxyRound_610x382
(Picture: Samsung)

Rumors that Apple is developing iPhones with 4.7 and 5.5-inch screens aren't surprising given that Google, Samsung, LG and HTC currently offer smartphones with 5-plus-inch displays. Witness 5.7-inch display that arrived in the Galaxy Note 3 "fablet" in September.

The other, and perhaps more interesting rumor coming from Bloomberg, is that Apple is experimenting with curved glass displays on its forthcoming iPhone models.

Samsung announced its curved-screen Galaxy Round last month (check out CNET's "Get bent" and ZDNet's photo gallery) -- essentially a concave Note 3 -- and some were quick to dismiss its curved glass as a marketing gimmick. While the iPhone user in me thinks that it smacks of a money grab by Samsung, a new report by renown display expert Dr. Ray Soneira maintains that there are tangible benefits to curved glass displays in consumer gadgets.

According to Soneira, slightly curved glass magnifies the sizes of all of the objects that it reflects which substantially cuts down on the interference of light reflections from ambient light. 

Introducing a slightly curved cylindrically concave screen is a very important and major innovation in Smartphone display technology - very far from being a marketing gimmick as has been widely reported. The Galaxy Round screen curvature is very subtle, just 0.10 inches away from flat, which is similar to the slight curvature in a handheld magnifying mirror. But that small curvature is the key to a series of optical effects that result in significantly reducing interference from reflected ambient light by a large factor. It substantially improves screen readability, image contrast, color accuracy, and overall picture quality, but can also increase the running time on battery because the screen brightness and display power can be lowered due to the reduced light interference from ambient light reflections.

So there you have it. This curved glass thing might have legs after all. If it increases battery life that alone might be worth the small penalty in overall device height that comes from curving an otherwise flat object. 

In related news, some speculate that Apple's recent purchase of $578 worth of sapphire and its construction of a manufacturing plant in Arizona could foreshadow a switch from Gorilla Glass to sapphire on the iPhone and iPad. Others believe that it could be for the iWatch.

When I asked Soneira about Apple's sapphire plans, he noted that it would be "good for both" (the iPhone and iWatch) 
"but very expensive." Adding "I believe sapphire is more scratch resistant than Gorilla Glass but don't know what its Reflectance properties are. My guess, based on the size of the investment, is that it will be for smartphones and possibly tablets. Watches alone probably wouldn't justify an investment of this size."

Matthew Hall, Director of the Center for Advanced Ceramic Technology at the Kazuo Inamori School of Engineering at Alfred University (via TechCrunch) notes:

Chemically strengthened glass can be excellent, but sapphire is better in terms of hardness, strength, and toughness. The fracture toughness of sapphire should be around 4 times greater than Gorilla Glass – about 3 MPa-m0.5 versus 0.7 MPa-m0.5, respectively.

Apple currently uses sapphire crystal for the Touch ID-enabled home button in the iPhone 5s.

Apple uses sapphire crystal for the iPhone 5s home button.

So, would you purchase a curved iPhone (over a flat iPhone?)

Topics: Apple, Google, Hardware, iPhone, iPad, Samsung

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24 comments
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  • Curved Glass

    Forty-five years ago a clothing shop in Piccadilly, London had curved glass in shop windows; the vividly displayed clothing was almost touchable with no reflections whatsoever from the glass.

    Personally I would prefer slightly thicker phone with flat sapphire glass but with bigger battery and non-prodruding camera gear [Nokia 1020's camera gear sticks out].
    Cheetah43
    • Sapphire - Additional benefits & info

      Cheetah, the type of sapphire discussed here is man-made from a very abundant substance, & with mass-production the price-differential could become a non-issue.
      --- Here is a Google+ link to additional information for Jason and readers:
      --- https://plus.google.com/114660584480111918841/posts/8LpLeAmxp3p
      Paul B. Wordman
  • the sapphire crystal in my watch...

    ... Blows gorilla glass away for durability and especially scratch resistance. I would love to see it used in more applications if the cost isn't ridiculous.
    Playdrv4me
    • Good point on scratch resistance

      especially because the concave front would lift the screen off the surface when facing down. Like-wise, the back would prevent the camera lens from touching the surface when facing up, if it's not positioned in the center.
      gamoniac
  • You forgot that sapphire is also used by Apple as camera protection

    However, it is not easy to grow sapphire crystals as a curved glass; doubtful.

    Besides, the increase of thickness of phone because of "curviness" is not slight, it is significant.

    Finally, "curviness" significantly and annoyingly distorts image under any angle besides strictly perpendicular.

    So this whole rumour is a tabloid speculation which is unlikely to ever come true.
    DDERSSS
    • @DDERSS

      You're right, the curved sapphire glass on fine watches are pretty thick. They might be able to use chemical vapour deposition on a curved surface though.
      Colbtron
    • Solution for distortion?

      Good insight--can the distortion be mostly corrected with combination of display software and the level?
      jmoore125
  • $578 of sapphire?

    That's not very much. Maybe they only need a very thin layer of sapphire to cover the screens? Like .0005 nanometers?
    Colbtron
    • it was supposed to be Millions of $$

      as in $578M
      ForeverSPb
  • Interesting....

    An "expert" that does not know what the Reflectance properties of sapphire are? Needless to say there are plenty of studies on that matter, available to anyone.... If he does not know these things, is his opinion any better than anyone else's?
    danbi
    • His opinion is.

      Because he didn't talk much about things he's unsure of. Unlike commenting on a webpage or making marketing presentations, scientists are trained to take the more conservative route when they are not 100% sure on a matter. He provided great knowledge on the curved-screen and some basic info about the sapphire.
      xelsm
  • Wish computer diplays were similarly curved!

    :-(
    kd5auq
  • I wouldn't buy iAnything...

    but it'll be interesting to see what Nokia comes up with.
    kstap
  • I wonder

    will a curved phone break if one puts a heavy text book on it.
    ForeverSPb
    • I doubt it.

      the curve is quite subtle so the weight would still be quite evenly distributed; and since we cant usually break our phones by bending it with our hands, it should be fine.

      Why would you put heavy text books on a phone though? it's as bad as asking "would my phone break if I park my car over it?" In which case you'd have to get a Nokia..............
      xelsm
  • Curved glass is more than a marketing gimmick

    I am curious about the strength of the curved glass and if the phone can hold up to the accidental drop. Will the curved glass make the phone stronger or weaker?
    Loverock.Davidson
    • Both.

      Screen can't touch the ground unless something pushes it the other way back on its sides then snaps!
      Raleigh Brecht
  • Use cases?

    My phone spends most of its time laying on my desk or on a table. I can reach over and use it one handed without having to grab it and hold onto it. Would I have to spend money to buy a cradle because curved screens don't address this very common use case? Curved screens on a mobile device are a usability fail.
    aep528
  • Reserving judgment...

    ...until I can hold, say a G Flex, in my hand. The whole issue of reflection management never occurred to me though so that was a useful bit to get out of this story.
    Gussy2000
  • Curved glass good for people for putting device in their pockets.

    I don't know if curved glass is a marketing gimmick but looking how many people like my son put his phone into their pockets which your body is curved I think this is good idea, however, which way should the curve bend? Curved with display in or out so if a person wants to protect the display may want the curve to bend into display and if person wants to view their display to look at the time will want to display to away the display so now manufactures will need to decide to make to types both curves devices or abandon part of consumers & make one type of curve. In my humble opinion, a flexible display/device which doesn't matter which direction the consumer wants.
    phatkat