Method for manufacturing lens-fitted photo film unit

A method of manufacturing a film unit having a cartridge chamber and a film roll chamber which hold a cartridge shell and a roll of photo filmstrip respectively, wherein the cartridge shell contains an entire length of the filmstrip before being exposed, and is able to advance the filmstrip out of the cartridge shell by rotating a spool of the cartridge shell in an unwinding direction, the method comprising the steps of:

• advancing the filmstrip out of the cartridge shell by rotating the spool through a spool drive shaft;
• stopping the spool drive shaft when the filmstrip is advanced a predetermined length out of the cartridge shell;
• detecting a rotational position of the spool at the stop of the spool drive shaft based on a rotational position of the spool drive shaft;
• disengaging the spool from the spool drive shaft while maintaining the rotational position of the spool and the advanced length of the filmstrip unchanged;
• engaging the spool with a film supply shaft, after adjusting a rotational position of the film supply shaft to the rotational position of the spool;
• securing the leading end of the filmstrip to a winding shaft when the spool is engaged with the film supply shaft;
• rotating the winding shaft to withdraw the filmstrip from the cartridge shell and wind the filmstrip into a roll;
• and
• loading the roll of the filmstrip and the cartridge shell in the film roll chamber and the cartridge chamber of the film unit respectively.