Impact printers are those printers in which a hammer and an inked ribbon strikes the paper to leave an image or mark a letter on the paper. Some examples of impact printers are:
- Dot-matrix printer
- Daisy-wheel printer
- Line printer
Dot-matrix printer is a type of impact printer that operates like a type writer. It has a print head which can run back and forth and strike an inked ribbon against the paper leaving the appropriate character, image, line or dot on the Paper. The quality of dot-matrix printer is determined by the number of pin heads it contains. There can be 9, 18 or 24 pins in a dot-matrix printer. dot-matrix printer with 24 pins provides the best printing quality. This printer scan produces both carbon and carbonless copies. The printing speed of a dot-matrix printer is about 50 to 600 characters per second depending on the quality of print. However, it produces a lot of noise while printing.
Line printer is a type of impact printer that can print one line at a time instead of printing one character at a time. It is a high-speed impact printer that can print over 3000 lines per minute. It is much faster than the dot-matrix printer and the daisy-wheel printer.
But the line printer has a major disadvantage, that it cannot print graphics. The quality of printing in line printer is low and it also produces a lot of sound while printing. There are two types of line printers:
Drum printer: Drum printer consists of a consistently rotating cylindrical drum W. here all the characters and numbers are raised and papers are inserted between the inked ribbon and hammer. When the desired character for the selected position rotates around the hammer, the hammer strikes the paper from behind and pushes it into the ribbon and that leaves an impression on the Paper.
Chain printer: A chain printer is similar to the drum printer but it uses a metallic chain instead of a drum. The chain consists of embossed characters and it horizontally in front of the paper. There are five sections in the metallic chain and in each section, there are 48 characters. Like the drum printer, the selected position rotates in the printer and when the desired character for the selected position rotates around the hammer, the hammer strikes the paper from behind and pushes it into the ribbon and that leaves an impression on the paper.
The chain printer is a very high-speed impact printer that can print 400 to 3000 lines per minute. However, this printer produces noise while printing as it prints the characters by a hammering action.
Plain paper: Plain papers are papers that are used for everyday use and can be printed on both sides. Plain papers generally have a thickness of about 65 to 99 gm/ sq. meters and they can be of various sizes like A4, legal or letter.
Carbon paper: Carbon paper is a type of paper which is used to make multiple copies of a document at a time. In any type of impact printer, a carbon paper can be introduced between the sheets of plain paper to make multiple copies of a document.
Tractor-feed paper: Tractor-feed paper has holes on the left and right end of the paper. It can be fitted in an impact printer that has two sprocket Wheels with removable and perforated side strips. This type of paper is generally used for multi-part stationery
Impact paper: Impact papers are generally used for printing bills. it Is generally used in departmental stores, hospitals, restaurants, etc.
Daisy-wheel printer Daisy-wheel printer was invented by David S. Lee at Diablo Data Syt,iorn in the year 1969. It operates in the same way as a ball-head typewriter, 1 hi!; type of impact printer has a disk which is made of metal or plastic contnining letters, numbers or any other character that it supports (see Figure 2). When it is required to print, the printer rotates the disk till the desired letter or number faces the paper. Then the hammer strikes the disk and forces the loiter or number to hit the inked ribbon that leaves an impression of that letter or number on the paper. Figure 2 shows the disk of a daisy wheel printer.
Daisy-wheel printer cannot be used for roduce printing graphics. Thisprinter can p different fonts but in such cases, it is p required to change the daisY wheels. However, it produces a lot of noise while printing and is very slow.