tailieunhanh - Mechanical Engineer´s Handbook P16

Tham khảo tài liệu 'mechanical engineer´s handbook p16', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 296 COMPUTER-AIDED DESIGN Resolution can be as high as 400 x 800 dpi with gray scales ranging from 16-128 values. These are medium- to high-throughput devices producing complex images in about a minute. On-board computing facilities such as RISC processors and fast hard disk storage mechanisms contribute to rapid drawing and processing speeds. Expansion slots accommodate interface cards for LANs or parallel ports. Inkjet Plotter. Inkjet plotters and printers fire tiny ink droplets at paper or a similar medium from minute nozzles in the printing head. Heat generated by a separate heating element almost instantaneously vaporizes the ink. The resulting bubble generates a pressure wave that ejects an ink droplet from the nozzle. Once the pressure pulse passes ink vapor condenses and the negative pressure produced as the bubble contracts draws fresh ink into the nozzle. These plotters do not require special paper and can also be used for preliminary drafts. Inkjet plotters are available both as desktop units for x 11-in. graphics and in wide format for engineering CAD drawings. Typical full-color resolution is 360 dpi with black-and-white resolution rising to 700 X 720 dpi. These devices handle both roll-feed and cut sheet media in widths ranging from in. Also ink capacity in recently developed plotters has increased allowing these devices to handle large rolls of paper without depleting any one ink color. Inkjet plotters are very user-friendly often including sensors for the ink supply and ink flow that warn users of an empty cartridge or of ink stoppage allowing replacement without losing a print. Other sensors eliminate printing voids and unwanted marks caused by bubbles in the ink lines. Special print modes typically handle high-resolution printing by repeatedly going over image areas to smooth image lines. In addition inkjet plotters typically contain 6-64 megabytes of image memory and options such as hard drives an Ethernet interface for networking and