Abstract: This invention provides an electrophotographic apparatus of the type wherein an upper unit open-/close-able with respect to a lower unit is provided with a sensitizing drum and a de-electrifying light source for eliminating residual potential on the sensitizing drum, which is characterized in that the de-electrifying light source is a membrane light emitting element, and this membrane light emitting element is movable so as to make open and closed the lower part of the sensitizing drum.

Abstract: In a pen recorder for obtaining desired recording data by pushing pen means mounted to a pen holder onto recording paper, the improvement comprising:(a) a feed mechanism for feeding said recording paper;(b) a moving pen holder for supporting said pen means; and(c) hammer means disposed at the rear of said pen means so as to bring the tip of said pen means into contact with said recording paper;(d) the tip of said pen means being fitted into support holes bored on a leaf spring fixed to said pen holder;(e) said leaf spring urging said pen means toward said hammer means;(f) said pen means being detachable relative to said pen holder;(g) said support hole of said leaf spring being shaped by expanding a part of a round hole in the direction opposite the pen withdrawing direction.