A power supply device for a sliding door includes an extra-length absorbing unit, a door side fixing unit fixed to a sliding door, a flexible tube extending from the extra-length absorbing unit to the door side fixing unit, and a wire harness wired from a vehicle body through the extra-length absorbing unit, the flexible tube and the door side fixing unit to the sliding door. Also included is an optical system focusing optical information onto the photosensitive system, and a display oriented to display optical information captured by the photosensitive system. The second leg is spaced inwardly from the end of the seat panel such that the work support can be used in multiple operating positions including supporting the seat panel: i) horizontally with the work support upright at one end; ii) upright with the work support similarly upright; or iii) upright with the work support transversely oriented at the top end of the upright seat panel.