PRINTERS

HP DESKJET 670C-ON MY PRINTER THERE ARE 2 BUTTONS. 1 FOR POWER WHICH IS ON WHEN THE PRINTER IS ON, THE OTHER IS JUST ABOVE IT AND HAS A CURLED PAGE ICON WITH AN ARROW. THIS LIGHT KEEPS BLINKING LIKE THERE IS SOMETHING IN THE QUE WAITING TO BE PRINTED. I HAVE NOTHING TO PRINT. WHY IS THIS LIGHT BLINKING?