The unveiling of the iPhone four nearly a year ago encompassed all of the usual Apple spectacle. New features, new design, and of course the two available colors: black and white. However, on launch day there was no white iPhone. Apple cited minor delays and that the phone would be available soon.
Then it was delayed again.
Apple apparently was struggling with production Alchemy. Except it didn't involved gold, rather it involved white paint and ultra violet rays.
According to Apple senior vice president Phill Schiller in an interview with All Things Digitals Ina Fried, there were "a lot of unexpected interactions between the color of the device and various internal components."
Those unexpected interactions meant the white iPhone needing more UV protection. The article doesn't go into specifics as to what those interactions were. A few hypothesis however cite the fact his is the first iPhone to have a white back beneath a layer of glass. The problems this presents are:
- Going from opaque black to translucent white allows light to enter the device. Previous white iPhone have been constructed of a solid piece of white plastic. Not a thin white layer recessed beneath glass
- Many of the sensors and the camera in the iPhone are recessed a few milimeters below the surface. Having a thin white reflective layer would be enough to deflect photons (basic unit of light) and affect the performance of sensors and the camera significantly.
A comment on the All Things Digital article seems to confirm this. A user named "Susan Parker" claims to have worked on the "Two axis optical tilt based sensor for the Air Pad gaming controller for the Playstation."
Everything was going fine in development until Parker's marketing team decided to change the color of the casing in the controller to a translucent grey to match the iMacs of the time. This forced Parker to redesign the optics module to be "light tight" to remain unaffected by intense ambient light conditions.
Apple of course will not release the specifics of how they solved the problem, leaving the rest of us to speculate. More will likely be known when ifixit or another website finally gets their hands on a production model and proceeds to disassemble it.
Until then this is the best we get from Schiller:
It was challenging. It's not as simple as making something white. There's a lot more that goes into both the material science of it -- how it holds up over time... but also in how it all works with the sensors... We thought we were there a year ago, or less than that, when we launched the iPhone 4, and we weren't."
Sources: All Things Digital