An image reading device includes an image reading section, an image processing section, and a density reference member. The invention also provides a control method of the secondary battery. A through passage is provided in the center portion thereof. For the pivot shaft to depress toward the vehicle’s interior side with respect to the sleeve, a load exceeding a predetermined value works axially on the pivot shaft from the vehicle’s exterior side. The header data includes a sync code for the digital specific data; identification information; and relative position data associated with the intra-coded digital picture data, wherein the associated relative position data is indicative of a plurality of relative positions from a current nth specific data location on the medium to each of a n+1, n+2,.