“People want a bigger screen iPhone. Are you against that?”

The Wall Street Journal’s Daisuke Wakabayashi asked Tim Cook. And here’s Cook’s response:

What we’ve said is that until the technology is ready, we don’t want to cross that line. That doesn’t say we’ll never do it. We want to give our customers what’s right in all respects — not just the size but in the resolution, in the clarity, in the contrast, in the reliability. There are many different parameters to measure a display and we care about all those, because we know that’s the window to the software.

Until the technology is ready? Very interesting.

1920×1080 LCDs start a 4.7 inches. Is Apple waiting for more pixels? Could be, because clarity, contrast, and reliability are all there. Or perhaps Apple is waiting for OLED. Contrast has been there for quite some time, but not the other three. RGB-striped 1920×1080 allows for class-leading clarity for text, but a 5.x-inch RGB-striped 1920×1080 OLED is still difficult and can’t be found on any mass manufactured smartphone available today. PenTile OLED displays with 1920×1080 equivalent pixel formats are more than good enough for most, but maybe not for Apple, not yet anyway. OLED reliability is also limited relative to LCD, only because the blue doesn’t last as long. But soon blue’s lifetime to half brightness might be good enough, for Apple too.

But there’s one other important consideration. And it depends on how we will be using larger smartphones in the future. RGB-striped OLED consumes more power and less power than LCD, depending on how you use it. If you watch video, which is generally darker than non-video, OLED will consume less power than LCD. The exception might be some computer animated features — such as Frozen — that are bright. If on the other hand you’re playing Flappy Bird on your 5.x-inch OLED smartphone the LCD equivalent will consume less. The only sure thing is with a large 5.x-inch OLED smartphones we’ll be doing a lot more of what we’re doing right now.

Apple, along with other companies wanting to incorporate large RGB-striped OLED displays into their smartphones, will need to wait until battery technology improves to a point where large 5.x-inch OLED smartphone usage models point to the battery lasting at least an entire day. That might not happen for a while, but I’m looking forward to what Apple has in store with the iPhone 6.