Abstract: A method is presented of erasing, in a document data processing device, a stored information pattern on a rewritable data carrier that is accessible by a data processing facility of the document data processing device. The document data processing device includes primary processes for processing document data, wherein data may be stored on the data carrier, and secondary processes for erasing stored data, through overwriting a selected storage area of the carrier by a shredding pattern. According to the method, the primary and secondary processes are run asynchronously, e.g., the secondary processes are run in background, in order not to hinder the primary processes. In a particular embodiment, an initial shredding run is made directly after a file is no longer used, and additional shredding runs are made in background.

Abstract: According to an embodiment, a method is presented of erasing, in a document data processing device, a stored information pattern on a rewritable data carrier that is accessible by a data processing facility of said device, the document data processing device having primary processes for processing document data, wherein data may be stored on the data carrier, and secondary processes for erasing stored data, through overwriting a selected storage area of the carrier by a shredding pattern. According to the method, the primary and secondary processes are run asynchronously, i.e. the secondary processes are run in background, in order not to hinder the primary processes, and the progress of the erasing process is dynamically displayed for the operator to give an indication of an internal data security situation.

Abstract: A method is presented of erasing, in a document data processing device, a stored information pattern on a rewritable data carrier that is accessible by a data processing facility of the document data processing device. The document data processing device includes primary processes for processing document data, wherein data may be stored on the data carrier, and secondary processes for erasing stored data, through overwriting a selected storage area of the carrier by a shredding pattern. According to the method, the primary and secondary processes are run asynchronously, e.g., the secondary processes are run in background, in order not to hinder the primary processes. In a particular embodiment, an initial shredding run is made directly after a file is no longer used, and additional shredding runs are made in background.

Abstract: In a process for the formation of an electrostatic image on a photoconductive element comprising a photoconductive zinc oxide-binder layer and an insulating top layer, the top layer is first positively charged and then is negatively charged until the element is saturated with negative charge, after which the top layer is imagewise exposed to light.

Abstract: A stable panchromatically sensitized zinc oxide having a low moisture sensitivity with dark discharge properties rendering it suitable as the photoconductive material of elements for indirect as well as direct electrophotography is produced by reacting finely divided zinc oxide with gaseous ammonia and carbon dioxide, while keeping the zinc oxide particles in motion, until a critical stage is reached corresponding usually to a weight increase of 4 to 7.5%, at which point the reacting is terminated and the product is heated to constant weight at a temperature between 190.degree. and 350.degree. C. Photoconductive elements made with the panchromatically sensitive zinc oxide not only are reusable indefinitely under varying atmospheric humidity conditions without loss of their sensitivity, but also exhibit a memory effect much lower than that of known photoconductive zinc oxides.