Patent ID: 8876248

Claim:
A detecting method for printing material boundary of a large UV inkjet printer, comprising steps of: placing a printing material on a printing rail of the large UV inkjet printer; performing a full-field scanning process by a photosensitive element of a sensing device moving along a first direction at a first scanning speed, the photosensitive element receiving reflected light from different positions below to cause the sensing device to produce corresponding induced voltage signals sequentially; determining rough coordinate positions of two opposite sides of the printing material based on the changes of the induced voltage signals, and defining detailed scanning areas including the rough coordinate positions of the two opposite sides; and after performing the full-field scanning process, performing a detailed scanning process for the detailed scanning areas by the photosensitive element at a second scanning speed slower than the first scanning speed when the photosensitive element moving along a second direction opposite to the first direction and passing the detailed scanning areas in order to obtain boundary coordinate positions of the two opposite sides of the printing material based on the changes of the induced voltage signals.