Nearly all modern cell phones have the same touch-screen form factor.
Except for a few buttons of low importance (e.g. volume adjustment, power, camera shutter), all interaction is done through the screen itself.
This style of interaction makes use of only one finger, and leaves the remaining four fingers with nothing to do (except hold the phone).
It can also be difficult to reach across the entire phone with one thumb. Finally, one’s grip of the phone is significantly diminished when interacting with the phone, making it easier to drop it during interaction with an app or web page.
Fig 1: Modern phones typically have a form factor similar to the one at left. Right: when holding the phone, the thumb (labeled “5”) does all the work, while fingers 1–4 flop about uselessly on the opposite side of the phone.
Proposal: additional hardware keys on the phone edges
In order to improve phone-handling characteristics, we can add easy-to-press hardware keys to the edge of the phone.
Let us assume that this phone will be intended for right-handed operation. See figure 2 for the proposed button layout.
Fig 2: On the left edge of the phone, four keys (one for each finger) are added.
On the right edge of the phone, a slideable switch is added. This acts as a scrollwheel; it can be pressed in to click, or slid up or down to scroll a web page. This is an old idea seen most notably in the “thumb scrollwheel” in Blackberry phones ~2000–2010.
Slight downside: these new features are unusable when the phone is held in the left hand.
Fig 3: The new buttons on the left (numbered 1–4) would allow for typing in the fashion of a chorded keyboard (https://en.wikipedia.org/wiki/Chorded_keyboard). With 4 buttons, we have (2^4 – 1) = 15 possible letters.
Fig 4: If full typing ability is desired, it would be possible to make the buttons into rings instead, allowing the buttons to be pulled out instead of just pushed. Now we are up to (3^4 – 1) = 80 possible combinations of letters when typing in a chorded keyboard fashion. This is more than enough for any alphabet.
(Note: the thumb ring in this diagram would need to pivot in order to allow a comfortable grip.) would have to be rotated almost 90 degrees to allow for a comfortable grip.)
Although this new interaction style could take some time to get used to, it would greatly improve phone interaction efficiency.
PROS: Makes phone interaction faster. Makes it easier to hold the phone in a secure grip.
CONS: If no one drops their phones anymore, phone case manufacturers may go out of business.