Structure for automatically measuring paper width for printer

A structure for automatically measuring a paper width for a printer, comprising:

• a width adjustment mechanism installed in the printer and at least one restraint arm driven by the width adjustment mechanism, wherein an inductor is also arranged inside the printer, the width adjustment mechanism or the restraint arm comes into contact with the inductor when sliding unidirectionally, and the inductor outputs a corresponding displacement signal;
• wherein the width adjustment mechanism comprises an adjustment gear and a right rack and a left rack meshing with upper and lower ends of the adjustment gear respectively, a restraint arm is fixed at each remote end of the right rack and the left rack, and an upper end surface of the right rack comes into contact with the inductor when sliding under drive of the adjustment gear;
• wherein the inductor is a multipoint contact induction sensor, and a distribution direction of contact points on a surface of the contact induction sensor is consistent with a sliding direction of the right rack.