What's the difference between printer, copier and all-in-one machine?

Printers can only print, which is the basis of office equipment. Mainly divided into needle printers, inkjet printers, laser printers and thermal printers. Different printers have different working principles and printing functions: stylus printers print character graphics through physical contact between printers and paper; An inkjet printer prints character graphics by ejecting toner; The laser printer prints character graphics through the carbon powder in the toner cartridge; The thermal printer selectively heats the thermal paper at some positions, thus producing corresponding graphics.

Copier literally means a printer with copying function. Copying machines do not need other intermediate means, such as plate making, and directly obtain copies with equal scale enlargement, enlargement or reduction from written, drawn or printed manuscripts. Copying machines can be divided into three categories according to their working principles: photochemical copying, thermal copying and electrostatic copying.

(1) Photochemical copy includes direct copy, blueprint copy, diazo copy, dye transfer and diffusion transfer. Direct photocopying method is to use Gao Fancha photographic paper instead of photosensitive film to shoot the manuscript, which can be enlarged or reduced; Blueprint method is to coat the surface of copy paper with iron salt, and then expose a single manuscript made of translucent materials and develop it to form an image with white characters on a blue background. Diazo method is similar to blueprint method. The surface of copy paper is coated with diazonium compounds, and after exposure, it is developed in liquid or gaseous ammonia to produce dark-tone images. Other photochemical replication principles are the same as above.

(2) Thermal copying is to paste copy paper coated with thermal sensitive materials on a single original and receive infrared or heat source irradiation. The heat absorbed by the image part is transferred to the surface of the copy paper, which darkens the tone of the heat-sensitive material and forms a copy. This copying method is now mainly used for fax machines to receive faxes.

(3) Electrostatic copying is the most widely used copying technology at present. It is made of selenium, zinc oxide, cadmium sulfide and organic photoconductor, which are charged in the dark to form an electrostatic latent image, and then developed, transferred and fixed. Electrostatic copier is an office equipment which integrates electrostatic imaging technology, optical technology, electronic technology and mechanical technology.

All-in-one machine is based on printer and has many functions. A printer plus a scanner is a printer and copier. Printing, copying and fax machines are added to the fax function. Copying machine and all-in-one machine are basically the same in working principle, but they are completely different from the perspective of internal structure and maintenance.