You’re able to set a passcode lock to your account. Instead of logging out you’ll then lock your account. When returning to your workstation you will be able to login by using your passcode. Also, when the account locks automatically after a certain amount of time for security reasons, you will be able to login with your four digit passcode.
This accounts for desktop, tablet (iPad) and mobile (iPhone).
To start, open Menu > App settings > Users > Login details
Next, select change passcode. Follow with enabling passcode and enter your desired four digit passcode and repeat this passcode. Finalise by providing your login password.