A retainer ring includes at least two holding sections and at least one engaging section. The image processor is provided with an input supplementation buffer which stores the input image signals of a plurality of lines, an input data buffer which stores input image signals required to generate the intermediate image signal corresponding to one line, and a number-of-supplementary-lines calculator which calculates the number of supplementary lines of the input image signals. Moreover, the microtip comprises a longitudinal conducting core having an essentially constant cross-section. The extruded components perform fence component positioning and establish pre-determined dimensioning and locations of the accompanying parts and pieces of the complete fence system and provide for component attachment that is not visible when the fence installation is completed. The flexible binding material can also be used to temporarily bind pre-punched pages of a book by inserting the flexible binding material into the pre-punched holes to facilitate lay-flat opening of the book. As a result, data is rewritable on a memory cell basis without increasing the memory cell size.