A line printer prints one entire line of text before advancing to another line.[1][2] Most early line printers were impact printers.
Line printers are mostly associated with unit record equipment and the early days of digital computing, but the technology is still in use. Print speeds of 600 lines-per-minute[3] (approximately 10 pages per minute) were achieved in the 1950s, later increasing to as much as 1200 lpm. Line printers print a complete line at a time and have speeds in the range of 150 to 2500 lines per minute.
The different types of line printers are drum printers, band-printers and chain printers. Other non-impact technologies have also been used, as thermal line printers were popular in the 1970s and 1980s, [4] and some inkjet and laser printers produce output a line or a page at a time.
Designs
Many impact printers, such as the daisywheel printer and dot matrix printer, used a print head that printed a character then moved on until an entire line was printed. Line printers were much faster,[5] as each impact printed an entire line.
There have been five principal designs:
Drum printers
Chain (train) printers
Bar printers
Comb printers
Wheel printers
Because all of these printing methods were noisy, line printers of all designs were enclosed in sound-absorbing cases of varying sophistication.