Projection apparatus and calibration method

A projection apparatus, comprising:

• a lens module, having a tele mode and a wide mode, and adapted to focus an image beam on a reference plane in one of the tele mode and the wide mode;
• a movement element, adapted to adjust a position of the lens module;
• a sensing element, adapted to detect the position of the lens module;
• and
• a lens control element, electrically connected to the lens module, the movement element, and the sensing element, wherein:
• when the movement element drives the lens module to move to the origin position, the lens module triggers the sensing element, the sensing element provides an origin-position information signal to the lens control element, the lens control element controls the movement element to stop the lens module from moving, and the lens control element sets the movement parameter value of the movement element to an origin parameter value, the lens control element controls the image beam to focus on a first position on the reference plane in one of the tele mode and the wide mode, and the lens control element controls the image beam to focus on a second position on the reference plane in the other of the tele mode and the wide mode;
• the lens control element determines whether an offset exists between the first position and the second position;
• when the lens control element determines that an offset value exists between the first position and the second position, the lens control element correspondingly adjusts a movement parameter value of the movement element in the one of tele mode and the wide mode based on the offset value between the first position and the second position, so that the image beam is focused on the same position on the reference plane in the tele mode and the wide mode that have been adjusted.