You could try to type-in the name of your printer inside Spotlight, the interface showing up should let you click on the "Scanner" button.
The quickest way I found so far; and I don't think you can get to that "scanner-button-interface" directly i.e: you have to go through the printer-interface.
(see How can I access my scanner directly without going through System Preferences?How can I access my scanner directly without going through System Preferences?)