Abstract: A highly efficient lighting system, a scrolling unit, and a projection system adopting the highly efficient lighting system and the scrolling unit are provided. The scrolling unit has at least one lens cell. From the viewpoint of light incident upon the at least one lens cell, the rotation of the at least one lens cell is converted into a rectilinear motion of a lens array, such that incident light is scrolled. The projection system includes a light source, an optical splitter, at least one scrolling unit, and a light valve. The optical splitter splits light emitted from the light source according to wavelenght. The at least one scrolling unit has at least one lens cell. The lens cell has an incident side and an emitting side and divides incident light into light beams. The rotation of the lens cell causes a rectilinear motion of the light beams, thereby scrolling incident light.