A medium feeding device includes a rib disposed on a feeding path along which the medium is fed. The present application further provides polyanthracene produced by methods described herein that has higher solubility in organic solvents and better thermal stability and ablation resistance. The oscillator further includes a control terminal for applying a control voltage by way of a resistor to the common connection point of the first terminals, and return resistors inserted between the second terminals of variable-voltage capacitance elements and the ground potential. The stripe of adhesive is covered with a release tape. Available versions of this sleek lamp include a variety of arm and joint configurations so that the lamp can serve a wide range of installations and applications, while using a standardized group of components.