Abstract: In the optical system of an electrophotographic copying apparatus embodying movable mirrors, it is of the utmost importance that these mirrors be properly aligned relatively to one another. In the present invention, two of the mirrors mounted at right angles to one another on a slidable frame which moves at half the speed of another movable mirror, are mounted on that frame for slight pivotal movement. This pivotal movement is controllable to provide adjustment of errors in the optical system and when adjustment is completed the mirrors are fixed in place.

Abstract: An electrophotographic reproducing apparatus in which a reproducing apparatus body unit including an electrostatic latent image receptor such as a photosensitive member and other electrophotographic treating device is assembled in advance whereas an optical scanning unit including at least a document illumination lamp, a group of mirrors and a group of focusing lenses is assembled in advance in a predetermined positional relationship to the reproducing apparatus body unit, and both the units thus assembled are jointed at predetermined reference planes to each other and so integrated that they can be driven cooperatively with each other. Said two units further include jointing device at their respective predetermined reference planes.

Abstract: A driving device for optical scanning unit of electrophotographic reproducing apparatus wherein a variable speed transmission of the driving mechanism of the optical scanning unit is installed on the outside of the drive mechanism mounting panel so that the desired speed ratio can be obtained by replacing the minimum amount of parts required.

Abstract: The present invention relates to a process for producing a 2-amino 4-acylaminophenyl ether by acylation of a 2,4-diaminophenyl ether with a good selectivity.