Sheet detection device and detection method thereof

A sheet detection device, incorporated with a sheet tray, the sheet tray comprising a sheet guide, the sheet detection device comprising:

• two magnetic sensing elements, disposed staggeredly to each other on the sheet guide along a moving direction, wherein when the sheet guide moves along the moving direction, the sheet guide is configured to bring the magnetic sensing elements to move to a first position or a second position;
• a first magnetic element, disposed on the sheet tray and corresponding to the first position;
• a second magnetic element, disposed on the sheet tray and in spaced with the first magnetic element, and corresponding to the second position;
• and
• a processing element, electrically connected with the magnetic sensing elements,
• wherein when one of the magnetic sensing elements is configured to output a first voltage signal corresponding to the first magnetic element, the processing element is configured to determine that the sheet guide is located at the first position according to the first voltage signal,
• when another one of the magnetic sensing elements is configured to output a second voltage signal corresponding to the second magnetic element, the processing element is configured to determine that the sheet guide is located at the second position according to the second voltage signal, and the first voltage signal is different from the second voltage signal.