If a system has a line printer, it can produce printouts of “hard copy.”Īn optical character recognition (OCR) system “reads” typed copy and records the characters on a machine-readable tape. Some systems have a video display terminal (VDT), consisting of a keyboard and a CRT viewing screen, that enables the operator to see and correct the words as they are being typed. The optical systems are supplanted in newer equipment by laser beams that form the various parts of each character in response to computer-generated electric pulses.
Light flashed through the characters projects them through a lens onto light-sensitive paper or film. It may be a grid, disk, drum, or film strip. Older typesetters have a photounit with an optical type font carried as a negative image or image master. The computer must be programmed carefully for optimal word spacing and correct hyphenation. The keyboard may be a counting keyboard, which allows the operator to decide placement and spacing and is suitable for tables, formulas, and equations, or a noncounting keyboard, which is faster and cheaper to operate and suitable for solid text. The system includes a keyboard that produces magnetic tape-or, formerly, punched paper-for input, a computer for making hyphenation and other end-of-line and page-makeup decisions, and a typesetting unit for output. Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.Ĭomputerized typesetting, method of typesetting in which characters are generated by computer and transferred to light-sensitive paper or film by means of either pulses from a laser beam or moving rays of light from a stroboscopic source or a cathode-ray tube (CRT).This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.
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