Abstract: A uniform thin replica film of a specimen for electron microscopy having a high resolution power such as approximately 1 A is presented. This uniform thin replica film is directly prepared on the specimen by a plasma polymerization technique by depositing organic monomer vapors on a specimen placed on a negative electrode in a high vacuum atmosphere. The deposition is carried out by applying a discharge voltage of from 0.5 to 3 K.V.D.C. between a pair of positive and negative electrodes for 1 to 15 minutes to effect a glow discharge under the conditions of a current density of the glow discharge of from 0.1 and 2 mA/cm.sup.2 and a gas pressure of from 1 to 10.sup.-2 Torr in the system.

Abstract: A printing mechanism of a line printer for printing Braille characters is disclosed. The printing mechanism comprises a base member having a plurality of printing pins arranged in a row and adapted to be prevented from moving downward in response to the energization of solenoids corresponding to character patterns to be printed, a semicircular printing plate for pressing a paper against the printing pins and a printing plate driving mechanism. During every printing operation, the printing plate is rocked in a lengthwise direction by a pair of rotating disks provided at the ends of the printing plate and each including an eccentric cam groove different in phase with each other, so that the paper is successively pressed against the printing pins in the direction of their arrangement and the raised dots are produced. In another embodiment of the invention, the printing plate is operated by a pair of piston-crank mechanisms provided at the ends of the printing plate.