Scanning device and homing method of scanning device

A homing method of a scanning device, wherein the scanning device comprises a scanning module moving along a moving-scan cycle direction, and the homing method comprises:

• disposing a positioning pattern on outside of a scanning window along the moving-scan cycle direction, wherein the positioning pattern comprises a first block, a second block, and at least one third block, the first block is associated with a positioning location, the second block is associated with a starting-scan location, and the first block, the second block, and the at least one third block are consecutive adjacent blocks with different pattern features;
• moving by the scanning module a first stepping distance toward the positioning location and detecting an acquired feature of a current location of the scanning module;
• determining by the scanning module whether the acquired feature of the current location is same as the pattern feature of the second block and switching to moving a second stepping distance toward the positioning location to detect the acquired feature of the current location;
• and
• determining by the scanning module the acquired feature of the current location being same as the pattern feature of the first block, and determining the current location being at the positioning location to stop at the positioning location.