Detector with triangle-shaped inductor coils

A document processing device, comprising:

• a feeding device to feed a number of sheets of media from a document tray and into a media feed path within the document processing device;
• and
• a detector to detect foreign objects within the number of sheets of media, comprising:
• a printed circuit board (PCB) comprising a number of triangular-shaped inductor coils.

A method of detecting a metal object coupled to a sheet of media entering a document processing device, comprising:

• applying an alternating current to a number of triangular-shaped inductor coils to create a magnetic field;
• detecting changes in a magnetic flux of the magnetic field as a metal object passes through the magnetic flux;
• and
• producing a warning when the changes in the magnetic flux are detected.