Patent ID: 8403782

Claim:
A printing apparatus comprising: a print head moving module comprising: a mounting plate, a first wheel attached to the mounting plate, a second wheel, an endless belt connecting the first wheel and the second wheel, and a retaining member slidably attached to the mounting plate and is adapted to clamp with the second wheel; an adjusting device comprising: a positioning member attached to the mounting plate, a driving member attached to the positioning member, comprising an indicating block, a moveable member slidably attached to the positioning member and abutting the retaining member, wherein the moveable member comprises a receiving portion; the receiving portion comprises a plurality of graduations; the indicating block extends through the positioning member and is received in the receiving portion; and a resilient member received in the receiving portion, and is between the driving member and the moveable member, wherein the driving member drives the moveable member and the retaining member away from the first wheel from a first position to a second position; if the moveable member and the retaining member are in the first position, the resilient member is in an original state, and the indicating block is away from a predetermined one of the plurality of graduations; if the moveable member and the retaining member are in the second position, the resilient member is deformed, and the indicating block is leveled with the predetermined one of the plurality of graduations.