Image erasing apparatus, and method of determining foreign matter attached to recording medium supplied to image erasing apparatus

An image erasing apparatus comprising:

• a supply unit that supplies a recording medium;
• a recovery unit that recovers the recording medium supplied by the supply unit;
• a carriage path on which the recording medium supplied by the supply unit is carried toward the recovery unit;
• a foreign matter information acquisition unit that includes a first conductive brush and a second conductive brush of which distal portions respectively come in contact with an upper surface and a lower surface of the recording medium carried on the carriage path;
• and
• a heating unit that heats the recording medium at a temperature equal to or higher than a color-erasing temperature of a developer at an erasing position which is on a downstream side of a carriage direction of the carriage path than an acquisition position of the foreign matter information acquisition unit.