An image scanner performing multiple scanning operations for a single scan line is disclosed. Later, when the user accesses the website again, the website may use the cookie, the cookie information, and additional information such as the stored IP address or NIC identifier to identify the user. The first sub-electrodes and the first connection parts are monolithically formed. The invention is characterized by feedbacking a change in a current value in accordance with the deterioration of a light emitting element and a power source voltage controller which modifies a setting voltage. For example, a video encoder adaptively switches between different motion resolutions, which allows the encoder to select a suitable resolution for a particular video source or coding circumstances. In one embodiment, a spinal screw extension instrument is provided having an outer component configured to engage a receiving member of a polyaxial screw.