2.  Optical Scanners Optical Scanners  Scanners Scanners  Electronic Tablet/Pen Electronic Tablet/Pen  Digital Camera Digital Camera  Webcam Webcam  Digitizers Digitizers  Speech Recognition Speech Recognition

3. Optical Mark Reader Optical Character Reader Bar-Code Reader Magnetic Ink Character Recognition Microphone

4.  These scanners are capable of recognising a prespecified type of mark made by pen or pencil.  The actual technique used by an OMR device for recognition of marks involves focussing a light on the page being scanned and detecting the reflected light pattern from the marks.  Pencil marks made with a soft lead pencil(high graphite content) will reflect the light.  For example:Consider sample question of an objective test and its answer sheet that can be read by an optical mark reader to grade the test is given below  The Binary equivalent of decimal 7 is a) 101 b) 111 c) 001 d)100 a) b) c) d)

5.  These scanner devices are capable of detecting alphabetic and numeric characters printed on the paper.  These characters may be either typewritten or handwritten.  In case of handwritten characters,the characters are of standard size, line making up the characters are connected and no stylish loops are used.  In case of Typewritten characters, they must be typed using a special type font called an OCR font.  OCR devices examine each character as if it were made up of a collection of pixels.  Once the whole character has been scanned, it is compared with the characters(standard fonts),the machine has been programmed to recognize.  Whichever pattern it matches, is considered to be character read.  If the Scanned character does not match satisfactorily with any of the fonts, it is rejected.

6.  It is a device used for reading(decoding) bar coded data.  Bar code reading is performed by a laser scanner which is linked to a computer.  The Laser beam is stroked across the Pattern of bits that is recorded as the input data.  Different bar codes having different patterns of bars reflect the beam in different ways that is sensed by a light sensitive detector.  Reflected light patterns are converted into electronic pulses and then transmitted to recognition logic circuits that convert it into an alphanumeric value.  The most widely known bar code is the Universal Product Code(UPC),which now appears on almost all retail packages in USA and now in India as well on many products.  These bars are decoded as 10 digits.  The first five of these digits identify the manufacturer or supplier of the product and the second five digits identify a specific product of the manufacturer.

7.  MICR devices were developed to assist the banking industry for fast processing of large volume of cheques  A Special type of cheque is used in banks that employ MICR devices.  The bank identification code and customer’s account number is pre-printed on all these cheques with a special ink that contains magnetizable particles of iron oxide.  Cheques can be fed directly into MICR device and processed automatically.

8.  It is an input device to input sound which is then stored in digital form.  This is then used for various applications like adding sound to a multimedia presentation or for mixing music. BACK

9.  Scanner is a light sensitive device that helps you copy or capture images, photos, and artwork that exist on paper.  A Scanner works on the principle of digitizing an image in the form of bit matrix called ‘bit-map’.  The bit-map can be stored in a file,displayed on the screen and can easily be manipulated by relevant packages/programs. BACK

10.  The tablet & pen in computer graphics describes an electronically sensitive tablet used in conjunction with an electronic stylus.  The tablet is a flat surface, seperate from the CRT screen,on which user draws with the penlike stylus to input instruction or to control the cursor.  It can also be used for selecting a portion of screen for enlargement of an existing image.  It can also be used for selecting a function menu.  It can also be used for Drawing on the screen or making stokes on the screen or tablet which indicates what image is to be drawn. BACK

11.  Digital cameras are used to: Download images to a computer Post pictures to the Web Produce videos  Resolution is measured in megapixels  Higher the resolution, better the image quality, but the more expensive the camera BACK

12. Web cam is a video camera that can be used to take images for uploading to the Web BACK

13.  A Digitizer is an input device used for converting(digitizing) pictures,maps and drawing into digital form for storage in computers.  It contains a large smooth board and an electronic tracking device which can be moved over the surface to follow existing lines.  The electronic tracking device contains a switch for the user to record the desired X and Y coordinate positions.  The coordinates can be entered into the computer memory or stored on an offline storage medium.  High Resolution digitizers typically with a large board(e.g. 42 in. by 60 in.) can provide resolution & accuracy on the order of 0.001 inch.  With the help of Digitizers,drawing can easily be changed. BACK

14.  Speech recognition is a type of input in which the computer recognizes words spoken into a microphone.  Special software and a microphone are required.  Latest technology uses continuous speech recognition where the user does not have to pause between words. BACK