INPUT DEVICES INPUT DEVICES Submitted by: Pradyumna Bhattarai 014BSCIT027.

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INPUT DEVICES INPUT DEVICES Submitted by: Pradyumna Bhattarai 014BSCIT027 Slide 2 INTRODUCTION : Is any machine that feeds data into a computer Reads the data in the form of text, numbers, image,audio or video But these data are converted to machine level languages i.e. in the form of 0 and 1. This devices will transmit data as a series of electrical impulses into the computers memory unit where it is available for processing The input devices translates the data into a code that can be read by the computers electronic circuitry. 2INPUT DEVICES Slide 3 Some of the input devices 1. Keyboard 2. Mouse 3. Track Ball 4. Joystick 5. Digitizing Tablet 6. Scanners 7. MICR 8. OCR 9. OMR 10.Speech Input Devices 11. Touch Screen 12. Touch Pad 13. Light Pen 14. Bar Code Reader INPUT DEVICES3 Slide 4 4 Slide 5 Keyboard Is an input device with various keys that enables to enter data into the computer Most common way to enter text and data Similar to the electronic typewriter but contains additional keys Nowadays, it has also been provided with feature to facilitate menu selection Standard layout is basically like typewriter keyboard (called qwerty Keyboard) and the first six letters spell QWERTY 5INPUT DEVICES Slide 6 Keyboard On the basis of layout, Keyboard are QWERTY and DVORAK Keyboard A. QWERTY Keyboard : The first six letters on the top row of letters spell as QWERTY. Designed in the 1800s Designed to slow typists down to avoid jamming the keys design is based on a layout created for the Sholes and Glidden typewriter and sold to Remington in 1873 INPUT DEVICES6 Latham Sholes's 1878 QWERTY keyboard layout Modern QWERTY Slide 7 Keyboard B. DVORAK Keyboard : The Dvorak layout was designed to replace the QWERTY keyboard layout Dvorak layout uses less finger motion, increases typing rate, and reduces errors compared to the standard QWERTY keyboard INPUT DEVICES7 Slide 8 Keyboard Commonly used keyboards : 1. 83 keys Original PC keyboard 2. AT (Advanced Technology Keyboard)- 101 keys 3. Enhanced Keyboard 103 or 107 keys Contains alphabets ( A to Z or a to z) Digits(0-9), special characters (!,@,#,$,%,^,&,*,,etc) And control keys (Ctrl, Alt, etc.) INPUT DEVICES8 Slide 9 9 Slide 10 Typing Keys: These keys include the letter keys (A-Z) and digit keys (0-9) which generally give same layout as that of typewriters. Numeric Keypad: Generally, it consists of a set of 17 keys which is used to enter numeric data or cursor movement. Function Keys: The twelve function keys are present on the keyboard which are arranged in a row at the top of the keyboard. Each function key has unique meaning and is used for some specific purpose. Control keys: These keys provide cursor and screen control. E.g. End, Insert, Delete, Page Up, Page Down, Control(Ctrl). Special Purpose Keys: Keyboard also contains some special purpose keys such as Enter, Shift, Caps Lock, Num Lock, Space bar, Tab, and Print Screen. 10INPUT DEVICES TYPES OF KEYS TYPES OF KEYS Slide 11 Mouse A device that controls the movement of the cursor or pointer on a display screen. Its name is derived from its shape, which looks a bit like a mouse, its connecting wire that one can imagine to be the mouse's tail, and the fact that one must make it scurry along a surface. It was invented by Douglas Engel Bart of Stanford Research Center in 1963. 11INPUT DEVICES Slide 12 12INPUT DEVICES Slide 13 TYPES OF MOUSE : Mechanical: It has a rubber or metal ball on its underside that can roll in all directions. Mechanical sensors within the mouse detect the direction the ball is rolling and move the screen pointer accordingly. 13INPUT DEVICES Slide 14 TYPES OF MOUSE : Optical: It uses a laser to detect the mouse's movement. They respond more quickly and precisely than mechanical and opt mechanical mice. INPUT DEVICES14 Slide 15 TYPES OF MOUSE : Opto- mechanical: It is same as a mechanical mouse, but uses optical sensors to detect motion of the ball. INPUT DEVICES15 Slide 16 AN OVERVIEW OF ANATOMY OF MECHANICAL AND OPTICAL MOUSE 16INPUT DEVICES Slide 17 Track Ball Invented by tom Cranston and Fred Longstaff as part of Royal Canadian Navys DATAR system in1952 Pointing device that works like an upside-down mouse Consists a ball housed socket containing sectors to detect rotations of the ball When the ball is rotated the cursor also moves Same function of mouse but instead of rolling the whole body only the ball is moved It requires less space compared to mouse 17INPUT DEVICES Slide 18 Track Ball 18INPUT DEVICES Come in different sizes and models On some portable computers they are built directly into the keyboard, slide out of the system unit in a small drawer, or clamp to the side of the keyboard Trackball Slide 19 Joystick Is also pointing device Used to move the cursor position on the screen with the help of the vertical stick Has spherical ball at its lower end as well as its upper end Lower spherical ball moves in a socket The cursor keeps on moving if it is not pulled again in the vertical position Different buttons are mounted to perform different commands Used for playing games, flight simulators, training simulators and for controlling the ROBOTS 19INPUT DEVICES Slide 20 Joysticks 20INPUT DEVICES Slide 21 Digitizing Tablet Is an input device that enables a user to enter drawings and sketches into computer Converts pictures, maps and drawings into digital form for storage into computer Consists of an electronic tablet and cursor or pen 21INPUT DEVICES Slide 22 Digitizing Tablet 22INPUT DEVICES Slide 23 Scanners A scanner is a device that captures images from photographic prints, posters, magazine pages, and similar sources for computer editing and display. When a document is scanned, it is converted into a digital format. This creates an electronic version of the document that can be viewed and edited on a computer. Most scanners include basic scanning software that allows the user to configure, initiate, and import scans. 23INPUT DEVICES Slide 24 Scanners 24INPUT DEVICES Slide 25 MICR Acronym of Magnetic Ink Character Reader Technology used to verify the legitimacy or originality of paper documents, especially checks The technology allows MICR readers to scan and read the information directly into a data-collection device 25INPUT DEVICES Slide 26 MICR 26INPUT DEVICES Slide 27 OCR Involves reading text from paper and translating the images into a form that the computer can understand i.e. ASCII codes It includes : Optical scanner: For reading texts Sophisticated Software: For analyzing images Examines each characters by analyzing the pixels of characters When the whole character is scanned, it is compared with standard characters that are stored in the OCR devices If a match is found, the character scanned is identified otherwise it is rejected from the device Advanced OCR can read text in large varieties of fonts, but they still have difficulty with handwritten texts 27INPUT DEVICES Slide 28 OCR.. OCR software is complex because it is difficult to make a computer recognize an unlimited number of typefaces and fonts Two standard OCR fonts are : OCR-A : American Standard OCR-B : European Standard 28INPUT DEVICES Slide 29 OMR Also called mark sensing Is a device which senses the presence and absence of mark Senses the marks by changing the intensity of light incidenting on the documents And receiving the reflected light from the document Intensity of reflected light is less than incidenting light. Hence,the presence of marks is known 29INPUT DEVICES Slide 30 OMR 30INPUT DEVICES Slide 31 Speech Input Devices New computers have features that enables them to record audio and video input and play it Speech input device include microphone So the instructions can be fed into the computer using these input devices Different speech recognization softwares are used to convert the input data into the machine readable form It is used for authentication of a user by a computer system based on the voice input 31INPUT DEVICES Slide 32 Speech Input Devices 32INPUT DEVICES Slide 33 Touch Screen Is an input device that allows the user to input the data or command by touching the screens Is a display which can detect the presence and location of the touch Can also sense the touch of other object like stylus Their use is becoming common nowadays Early touch screen can only sense the single touch but nowadays can sense multiple touch Commonly used in banks, restaurants, department stores, drug stores,etc. They are well suited for the simple applications such as Automated Teller Machine or Public information kiosks 33INPUT DEVICES Slide 34 Touch Screen 34INPUT DEVICES Slide 35 Touch Pad Also called as track pad Stationary pointing input device that many people find less tiring to use than a mouse Consists of the specialized surface that translates the motion and position of a user fingers to a relative position on screen Touch sensitive surface may be only 1.5 or 2 inches square, so a finger never has to move far Includes two or three buttons and functions same as mouse Must be kept dust free and oils free as it can harm the sensitivity Can be found on PDAs, portable media players, etc. Common features of the laptops INPUT DEVICES35 Slide 36 Touch Pad 36INPUT DEVICES Slide 37 Light Pen Pointing input device having the size and shape of regular pen Is used to select a displayed menu item or draw pictures on the monitor screen Can work with any CRT based display but not with LCD, projectors and other display devices. Used to identify the specific location Primarily used for graphics work Typical use is drawing the lines of various thickness INPUT DEVICES37 Slide 38 Bar Code Reader It is a photo-electric scanner that reads the bar codes. It consists of a light source, a lens and a photo conductor translation optical impulses into electrical ones. Bar code is an identification code printed in the form of light and dark bars with coded spacing and thickness which contains identifications of an item such as price, quality, manufacturer, etc. INPUT DEVICES38 Slide 39 INPUT DEVICES39