The timeout time is for the device to automatically go back to password protected mode if it has not been used for a while.
If you want to protect your homescreen, you need to install the password mode.
To activate the password mode after you are done doing what you have to do with your device, click on the the password lock icon.
8120 BIS 22.214.171.124
9700 BES 126.96.36.1996