Computer Input Devices Overview

Overview

This lecture introduces various computer input devices, their appearance, and their specific purposes in sending data to a computer for processing.

Introduction to Input Devices

• Input devices are computer components that send data to the central processing unit (CPU) for processing.
• Once processed, information from the CPU is sent to output devices.

Common Input Devices and Their Functions

• The keyboard is used to enter text into a computer.
• The mouse is a pointing device used to control the cursor on the screen.
• A joystick is commonly used for controlling video games, especially in play zones.
• The light pen is a light-sensitive pointing device used with old CRT monitors to highlight text.
• The trackball functions similarly to a mouse, but the user rolls a ball instead of moving the whole device.
• A scanner captures images for computer editing and processing.

Specialized Scanners and Readers

• Passport scanners are designed for fast scanning of documents like passports and ID cards, commonly used in airports and hotels.
• Pen scanners input printed text directly into the computer by sliding the pen over text, useful for capturing numbers or small text portions.
• Barcode readers scan printed barcodes, decode the data, and send it to the computer, widely used in shopping malls.
• OMR (Optical Mark Recognition) readers scan marked answers on OMR sheets (e.g., multiple-choice exams) for instant evaluation.

Graphics and Multimedia Input Devices

• Graphics tablets allow users to draw images by hand with a stylus for digital editing.
• Webcams record videos and enable live video streaming over the internet.

Key Terms & Definitions

• Input Device — hardware that sends data to a computer for processing.
• Keyboard — a device for entering text.
• Mouse — a pointing device for cursor control.
• Joystick — a control device for video games.
• Light Pen — a pointing device for CRT screens.
• Trackball — a stationary pointing device with a movable ball.
• Scanner — device that captures images or documents.
• Passport Scanner — scans official documents like IDs quickly.
• Pen Scanner — scans printed text into a computer.
• Barcode Reader — reads and decodes barcodes.
• OMR Reader — recognizes marks on answer sheets.
• Graphics Tablet — enables digital hand drawing.
• Webcam — records and streams video.

Action Items / Next Steps

• Review and identify the listed input devices and their functions.
• Prepare for a quiz on the types and uses of computer input devices.