US Patent No. 6,396,482 - Hand-held electronic device with a keyboard optimized for use with the thumbs
Looking for prior art related to claim 16:
A method of inputting characters into a mobile device having a keyboard and a display, the keyboard including a plurality of character keys and a space bar, the method comprising the steps of:
- (A) inputting a first set of characters into the mobile device using the keyboard, wherein the first set of characters comprise a first sentence;
- (B) selecting the space bar of the keyboard twice in succession and (1) displaying a period symbol (.) after the first sentence, and (2) instructing the mobile device to capitalize the next character input using the keyboard; and
- (C) inputting a second set of characters into the mobile device using the keyboard, wherein the second set of characters comprise a second sentence, and wherein the first character in the second set of characters is automatically capitalized by the mobile device.
Note the patent has a filing date of Jun 25, 1999, so any relevant art must have been published before this date. This patent has been assigned to RIM.
Basically, this claim is directed to the familiar feature on modern smartphones of double tapping the spacebar at the end of a sentence to automatically insert a period. Additionally, the next character typed will be automatically capitalized.

