The fi-4640S scanner offers scanning throughput in portrait mode of up to 40 letter-size pages per minute (ppm). The fi-4640S features a maximum output resolution of 800 dpi to capture the fine details of graphics and photos, while sophisticated dithering and diffusion algorithms deliver superior halftone rendering. For the ultimate in flexibility, the document feeder supports paper sizes as small as 2.1" x 2.9" and as large as 11.7" x 17". The 100 page ADF can be continuously fed without stopping the scan process to maximize efficiency. Prevent lost images due to document double feeds and ensure document batch integrity with the infrared detection feature. The fi-4640S scanner can be upgraded with a post scan, backside imprinter option. The imprinter can print 40 alphanumeric characters and includes one ink cartridge.