Abstract: An image reading apparatus reads an original-document image and generates image data of the original-document image, and includes an image reading unit, a security pattern detection unit, and a main control unit. The image reading unit reads the original-document image and sequentially generates the image data of the original-document image as a plurality of pieces of band data. The security pattern detection unit performs security pattern detection processing on band data of a single band to detect a portion or an entirety of a security pattern included therein. The main control unit causes the security pattern detection unit to perform the security pattern detection processing on band data of a single band having the lowest background color density and not on band data of a single band having the greatest background color density, among the plurality of pieces of band data.

Abstract: A file management device for a control system, has a file write unit which records data of a file into cluster areas of a recording medium, records file information into a directory area of recording medium, and records FAT chain information into FAT of recording medium; a file delete unit which stores file restoration information having the file information and FAT chain information into a memory area, sends back a restoration descriptor for identifying the file restoration information to control system, and deletes the file information and FAT chain information in recording medium; and a file restoration unit which reads data of deleted file from the recording medium based on the file restoration information and sends the data back to control system, and restores the file information and FAT chain information in the recording medium based on the file restoration information of the file selected by the control system.

Abstract: A file management device for a control system, has a file write unit which records data of a file into cluster areas of a recording medium, records file information into a directory area of recording medium, and records FAT chain information into FAT of recording medium; a file delete unit which stores file restoration information having the file information and FAT chain information into a memory area, sends back a restoration descriptor for identifying the file restoration information to control system, and deletes the file information and FAT chain information in recording medium; and a file restoration unit which reads data of deleted file from the recording medium based on the file restoration information and sends the data back to control system, and restores the file information and FAT chain information in the recording medium based on the file restoration information of the file selected by the control system.