Detection device, sheet position adjustment device, and corrugate machine

A detection device that detects a position of an edge of a band-shaped corrugated cardboard sheet in a width direction while the corrugated cardboard sheet is being transported, the device comprising:

• measurement means for measuring, within a measurement range including a predetermined measurement reference point of the corrugated cardboard sheet in the width direction and the edge on at least one side in the width direction, positions of a plurality of measurement points in a linear shape in the width direction;
• and
• specifying means for specifying, based on the plurality of measurement points measured by the measurement means, a true edge position in the width direction in a state where the corrugated cardboard sheet is not warped,
• wherein the specifying means calculates each of distances between the measurement points adjacent to each other, adds up all the distances to calculate a sheet width length from the measurement reference point to the edge, and specifies, as the true edge position, a position that is separated from the measurement reference point in the width direction by the sheet width length.