Size positioning device

A size positioning device applied to a window covering cutting apparatus, the window covering cutting apparatus having a cutting device for cutting a window covering, an output device, and a signal processing circuit electrically coupled to the output device and the size positioning device, the size positioning device comprising:

• a manual operating member;
• a limit assembly, configured to be connected to the manual operating member and drivable by the manual operating member to move, the limit assembly being provided to be abutted against by at least a first end of the window covering;
• and
• a position detecting device, configured to detect a position of the limit assembly and generate a position detecting value corresponding to the position of the limit assembly;
• wherein the position detecting value is transmitted to the signal processing circuit for making the signal processing circuit accordingly generate adjusted position information and target position information, and configure the output device to graphically display at least the adjusted position information;
• the target position information corresponds to a correct cutting size to which the window covering will be cut;
• the adjusted position information comprises at least one of current position information of the limit assembly and a comparison result of the current position information and the target position information;
• the manual operating member is manually adjusted according to the adjusted position information to move the limit assembly until the adjusted position information substantially equals the target position information, wherein whether the adjusted position information substantially equals the target position information is visually recognizable from the output device;
• after the manual operating member has been manually adjusted to move the limit assembly until the adjusted position information substantially equals the target position information, the signal processing circuit configures the cutting device to cut the first end of the window covering.