A scanner device for scanning mailpieces, which scanner device comprises: a contact image sensor or “CIS” disposed in a direction perpendicular to the conveying direction in which the mailpieces are conveyed through a module of a franking system; a support to which said sensor is fastened, the support being mounted to pivot at one end of at least one first drive lever, the other end of which is itself mounted to pivot about a first common hinge pin secured to a stationary portion of the module and disposed upstream from a set of conveyor rollers, so as to make it possible for said contact image sensor to move vertically; and at least one second drive lever one end of which is mounted to pivot about a second common hinge pin secured to said stationary portion of said module and disposed downstream from said set of conveyor rollers, the other end of the second drive lever, by being moved synchronously with the vertical movement of said set of conveyor rollers, moving the contact image sensor via the first drive lever.