k.b.h.polytechnic,malegaon camp, malegaon. computer hardware & maintenance. s.y.c.m/i.f guided...
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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.
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
April 21, 2023 7
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
April 21, 2023 8
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
April 21, 2023 9
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 2SAK3002 –
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 dpi 600 dpi 1200 dpi
Mr.K.S.Pawar
Chapter 2SAK3002 –
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 2SAK3002 –
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 2SAK3002 –
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 2SAK3002 –
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 2SAK3002 –
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 2SAK3002 –
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 2SAK3002 –
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 printspostage stamps
Most also print bar codes
Output Device (cont’d)
Mr.K.S.Pawar
Chapter 2SAK3002 –
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