K.B.H.POLYTECHNIC,MALEGAON CAMP, MALEGAON. Computer Hardware & Maintenance. S.Y.C.M/I.F Guided By :- Mr.K.S.Pawar. Lecturer in Computer Department

Chapter No :- 3 Input and Output Devices its interfacing Mr.K.S.Pawar

Mechanical Mouse A ball inside the mouse touches the desktop and rolls when the mouse moves. Mr.K.S.Pawar

Optomechanical Mouse Two rollers inside the mouse touch the ball. One of the rollers is oriented so that it detects motion in the X direction, and the other is oriented 90 degrees to the first roller so it detects motion in the Y direction. When the ball rotates, one or both of these rollers rotate as well. The following image shows the two white rollers on this mouse Mr.K.S.Pawar

Optical Mouse The rollers each connect to a shaft, and the shaft spins a disk with holes in it. When a roller rolls, its shaft and disk spin. The following image shows the disk typical optical encoding disk This disk has 36 holes around its outer edge. Mr.K.S.Pawar

Optical Mouse The disk there is an infrared LED and an infrared sensor. The holes in the disk break the beam of light coming from the LED so that the infrared sensor sees pulses of light. The rate of the pulsing is directly related to the speed of the mouse and the distance it travels.light closeup of one of the optical encoders that track mouse motion: There is an infrared LED (clear) on one side of the disk and an infrared sensor (red) on the other. Mr.K.S.Pawar

December 23, Scanners Primary used - to input paper images. A device that analyzes an image or an object (such as an ornament) and converts it to a digital image. Scanners are generally less expensive and more convenient. 3 primary types of scanners:  flatbed scanners,  sheet-fed scanners,  handheld scanners, but all 3 work similarly and differ only in the way the scan element is moved with respect to the paper. Mr.K.S.Pawar

December 23, Scanners In a flatbed scanner, the paper is placed on a glass window, while the scan element moves down the page, much like a copy machine. In a sheet-fed scanner, a single page of paper is propelled through the mechanism with rollers; the scan element is stationary. Handheld scanners are propelled by the user over the page. Mr.K.S.Pawar

December 23, Scanners The scanning mechanism consists of a light source and a row of light sensors. As the light is reflected from individual points on the page, it is received by the light sensors and translated to digital signals that correspond to the brightness of each point. Color filters can be used to produce color images. The resolution of scanners is approximately 600—2400 points per inch. Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application What is the resolution of a printer? Two basic types:  Impact  Non-impact Output Device (cont’d)  Printer  Sharpness and clarity  Measured by number of dots per inch (dpi) printer can output 300 dpi600 dpi1200 dpi Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Impact printer Output Device (cont’d)  Characters/graphics are formed on the paper by physical striking contact between ink ribbon and paper  Examples are dot-matrix printer (continuous paper), line printer (mainframe/minicomputer) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Nonimpact printer  Forms characters and graphics without striking paper Ink-jet printer  sprays tiny drops of liquid ink onto paper  Prints in black-and-white or color on a variety of paper types Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Photo printer  Color printer that produces photo-lab-quality pictures  Many photo printers have a built-in card slot Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Laser printer  High-speed, high-quality nonimpact printer  Prints text and graphics in very high- quality resolution, ranging from 1,200 to 2,400 dpi  Typically costs more than ink-jet printer, but is much faster Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Thermal printer  Generates images by pushing electrically heated pins against heat-sensitive paper  Dye-sublimation printer (also called a digital photo printer) uses heat to transfer dye to specially coated paper Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Mobile printer  Small, lightweight, battery-powered printer that allows mobile user to print from notebook computer, Tablet PC, or PDA while traveling Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Label printers and Postage printers  Small printer that prints on adhesive-type material  Postage printer has built-in digital scale and prints postage stamps  Most also print bar codes Output Device (cont’d) Mr.K.S.Pawar

Chapter 2 SAK3002 – Information Technology and Its Application Plotter  Sophisticated printer used to produce high-quality drawings  Large-format printer creates photo-realistic-quality color prints Output Device (cont’d) Mr.K.S.Pawar