An active type of display panel arranged with light-emitting elements such as organic electroluminescent elements, capable of effecting correct tonal display even during a long-time use, a display device using the display panel and a method of driving the display panel. A rib guide is formed as part of the outer wall and defines an opening extending through a bottom surface of the outer wall and including a first portion extending in a first direction and a second portion extending in a second direction that is non-parallel to the first direction. The invention further relates to corn seeds and plants produced by crossing plants of variety I217345 with plants of another variety, such as another inbred line. One of the aforementioned edges has a first projecting locking element which engages in a corresponding first cavity or recess of the other edge when the two panels are joined together. The second member has a tapered forward end portion that allows the second member to smoothly slide under the bottom of the stack of print medium. More particularly, embodiments of the present invention may provide a negative voltage for erasing when coupled to a memory cell to be erased and provide voltages to read or program when not coupled to a memory cell that is selected to be erased.