Abstract: A wobble detection device includes a sensor unit. The sensor unit includes a one-dimensional image sensor and a one-dimensional image sensor arranged side by side in an auxiliary scanning direction so that their corresponding pixels coincide with each other in a main scanning direction, and acquires an image of an object moving in the auxiliary scanning direction as one-dimensional data. The wobble detection device makes a comparison of data corresponding to the same image region by using one-dimensional data acquired by the one-dimensional image sensor and one-dimensional data acquired by the one-dimensional image sensor and thereby detects a movement amount of the image in the main scanning direction between a time when the one-dimensional data used for the comparison was acquired and a time when the one-dimensional data used for the comparison was acquired.