Dot matrix printer and print agency principle

Dot matrix printer and print agency principle
Each print pin is made of a rigid, metallic material toughness is very good, moves back and forth along the guide rail, power from the electromagnetic armature movement forward (forward) to promote and mechanical spring reverse (back) push, when The solenoid coil generates a magnetic field in a given pulse current (corresponding need to print a dot), the solenoid armature moves forward in this magnetic field, pushing the print pin also move forward and strike the ribbon; when the coil After the current disappears, the magnetic field disappeared, the electromagnetic force of the armature lost, mechanical spring reverse thrust to push the needle back to the original printing position. Since a plurality of printing needles can be driven simultaneously, so a single print is a longitudinal array of dots of a character, after the print head moves to the right position of a point, you can print the next point array of characters, after a few Print a complete character; and then control the print head is moved a certain distance to the right, you can start the next printing character, until you have printed all the characters on the line. Next is the paper feed mechanism controls take the paper, the print head back to the left side of the printer, the print process starts the next line of characters.

Some dot matrix printer has its own print buffer memory control logic circuitry. Print control logic is more important font generator, including Western and Chinese character dot-matrix information base; a buffer memory for storing CPU sent to be printed character coding, coding capacity of at least one line of characters can be stored now The printer is usually much more content can be stored; such a relatively small amount of information transferred between the CPU and the printer by encoded characters lattice information to find it is done in the printer control logic circuits and use them pin dot matrix print information control movement. When using dot matrix printer to print graphics, image is, CPU must directly lattice information graphics, images to control the movement of the print needle. Thus, character dot matrix printers and CRT monitor works have much in common, the difference is mainly manifested in: CRT character display using electron beam strikes the phosphor to produce light-emitting point, dot matrix printer is used to produce printing ribbon print needle hit points ; after CRT monitor in full-screen character information to maintain a stable unit continuously scans the display screen, so it needs a display memory VRAM, and dot matrix printer receives a dot column to be printed information and complete the print, these dot matrix information is no longer useful; grating literacy CRT character display, an electron beam across the screen-by-ridden repeat scanning, scanned a plurality of transverse show only complete line of characters, dot matrix printer is the print-by-column mode so print out the dot arrays of characters, several times after printing a complete character.

Dot matrix printer can complete color printing, which uses a color ribbon by the three strips of different colors, and can be in the printing process by moving up and down the ribbon, so that the different colors of thermal printer ribbon bars were under the printhead, which Print out the different colors of the characters. Color dot matrix printer application is relatively small.