Course Outline Input Unit Keyboard, Mouse, Scanner, OMR, OCR, MICR Barcode reader Microphone Joystick Digital Camera Light Pen Track Ball

Input unit: Keyboard One of the most common input device Type: QWERTY Number of keys: From 102 to 108/110 Function: Primary device for entering text and numbering

Input unit: Keyboard

Input unit: Keyboard Description: `QWERTY` keyboard The name of this keyboard comes from the first 06 alphabets placed at the top Keyboard adapter contains `8-bit ASCII code` micro- processor sends keystroke through BUS.

Keyboard There are 06 types of keys: Alphanumeric key Modifier key Function Key Numeric Keypad Cursor Movement Key Special Purpose Key

Input unit: Keyboard Description: Alphanumeric keys It includes over 50 keys consumes most of the area of keyboard Ex: A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z, -,=,+,<,>,$,{,[,},@,$,%,^,& etc Besides there are 04 keys whose have special purpose like `TAB,ENTER,CAPSLOCK,BACKSPACE`

Input unit: Keyboard Description: Modifier keys Some keys modifies the input of other keys Example: Shift, Alt, Ctrl Application: In MS Word if you press (Ctrl and A) immediately then all the written text will be selected. Here alphabet `A` will be modified due to “Ctrl” key.

Input unit: Keyboard Description: Numeric keypad Usually located at the right side of the keyboard like calculator keys There is a key called `Num Lock`. When it is off keypad performs as cursor movement Example: 1,2,3,4,5,6,7,8,9,0,/,*,.,-,+ etc

Input unit: Keyboard Description: Function keys Located at the top row of the keyboard Usually with this we can input command without typing long strings Their function varies with the variation of running program There are 12 function keys like F1, F2, F3,……..F12 For almost all programs, F1 = Help

Input unit: Keyboard Description: Cursor-movement keys With the help of these keys we can move the cursor or Insertion point according to our desire Example: keys marked with arrows Others are: Page up, Page down, Home, End

Input unit: Keyboard Description: Special purpose key They are desired to work with `Operating system` Example: “Windows logo key” usually used to start windows operating system Besides there is another key whose work is as like as ` Right button` of mouse Rests are: ESCAPE, INSERT, DELETE, PRINT SCREEN, SCROLL LOCK, PAUSE

How keyboard works?

How keyboard works? It's a complex function, described below- Suppose, a key is pressed on keyboard The` keyboard controller` sends the scan code for that key to the `keyboard buffer` The keyboard controller sends an `interrupt` request to the system software The `system software` responds to the interruption.

How keyboard works? 5. The system software can read the scan code from keyboard buffer that’s why it can respond. 6. The system software passes the scan code to CPU 7. Then for an input key we can see the output result

Continuous pressing of key……… There is a standard & specific time to show output for a key , when a key is pressed for more than that time, after a definite time it thinks that the key has pressed again. The same steps what it followed starts to follow again. Thus we see the same output consecutively.

Input device: Mouse A mouse is a `pointing device` An input device that rolls around on a flat surface and controls the pointer. Used to control the position of the cursor There are 02 types of mouse- Mechanical Optical A standard mouse has 02 buttons and a scroll Mechanical mouse has a ball (also call `ball mouse`) and Optical mouse has 02 light sources Mechanical mouse contains a small rubber ball that moves in a hole in the bottom of the mouse’s case. Optical mouse emits a beam of light from it’s underside and uses light’s reflection to judge the distance, direction and speed of it’s travel.

Mouse The optical mouse actually uses a tiny camera to take 1,500 pictures every second. The mouse has a small, red light-emitting diode (LED) that bounces light off on the surface underneath onto a CMOS sensor. The CMOS sensor sends each image to a digital signal processor (DSP) for analysis. The DSP is able to detect patterns in the images and see how those patterns have moved since the previous image. Based on the change in patterns over a sequence of images, the DSP determines how far the mouse has moved and sends the corresponding coordinates to the Computer. The computer moves the cursor on the screen based on the coordinates received from the mouse.

Input device: Mouse

Input device: Mouse Function: A mechanical mouse has some sensors inside it, with the help of ball they are touched and moved to change the position of the cursor An optical mouse has 2 sensory light sources, the amount of `light reflected` from surface determine the position of X-Y axis in the monitor

Variants of Mouse Track Ball Track Pad Pointers in the keyboard

Track Ball A trackball is like a mouse turned upside-down. Use your thumb to move the exposed ball and your fingers to press the buttons. Take less space than mouse.

Track Pad A trackpad is a touch-sensitive pad that provides the same functionality as a mouse. To use a trackpad, you glide your finger across its surface. Trackpads provide a set of buttons that function like mouse buttons.

Pointers in the Keyboard An integrated pointing device is a built into the keyboard. Users do not need to move the finger out of the keyboard while typing. These devices provide a set of buttons that function like mouse buttons

Mouse Techniques Single click: Double click: to select any file or folder Double click: to open an icon/file/folder Dragging: (also called Drag-&-drop-editing) To drag an item and place It in a new position for further operation Right click: Usually opens a shortcut menu which contains commands and options.

Advantages of mouse To select or open any file or folder without using cursor movement key 2. Sometimes to input command without using keyboard

Input device: Scanner They are mostly used to input prints, photography etc directly inside the computer There are three types of scanner- Flatbed: Hand Held

Scanner Flat Bed: Large, Not Portable: can't be carried but a large size image can be scanned in single scan Costly

Scanner Hand hold: Small, Portable: can be carried but a large size image can not be scanned: need multiple scans Less Costly

Scanner (How it works?)

Scanner (How it works?) A light source is moved across the page The light bounces of the page & is passed through a lens.. Light sensitive Diodes convert reflected light into electric signal. Circuit board converts the electric signals into digital numbers & sends the information to the computers Overall, sensing the intensity of light reflection is important here

Variants of Scanners The colour scanners use filters to separate the components into `Primary additive colours`( RGB- means Red, Green, Blue). RGB can be combined to produce any type of other colors. Image Scanner: Converts any printed image into electronic form by shining light onto the image and sensing the intensity of the light’s reflection at every point.

Input device: OCR Means `Optical Character Reader` Generally it is used in the banks, with the help of OCR the complex process of deposit & withdraw of money can be done easily & quickly OCR requires- 01. Specified symbol 02. Specified ink 03. Specified paper

OCR OCR software can be used to translate the image into text that you can edit. Image is stored at computer’s memory as a form of bitmap that is a grid of dots. Each dot is represented by one or more bits. OCR translate the array of dots into text. OCR is extremely complex and not always 100% reliable.

OCR (How it works?) Light ray scan the paper and the light is reflected back Reflected ray is converted into electric signal by light sensitive diodes A circuit board converts the electric signal into digital numbers and send it to CPU CPU taking data calculate it i.e. addition or deduction of numbers and show output

Input device: OMR Means- `Optical Mark Reader` Generally used to examine the objective type questions, also do other functions Requires: Specified paper Specified ink Working procedure is as like as OCR

Input device: MICR Means- `Magnetic Ink Character Reader` This system can read data pre-recorded on checks & deposit slips with a special ferrite-impregnated ink. The magnetized character can be read & interpreted by MICR equipment Primary means of processing checks Can read numeric characters and special symbols printed with magnetic ink

Input device: MICR Requirements: Cheque routine symbol Bankers transit number Customer account number Cheque number Cheque account

MICR: Advantages Human involvement is minimal Error chance is less It is fast, automatic and reliable If there is any mistake, then automatic detection of error

Input device: Barcode reader A device for reading barcodes of different width and spacing with same length Generally used in the departmental stores & industries to identify goods Barcode reader has organized primarily with a light source & a light sensor which connected with the CPU through cable

Barcode reader: (How it works?) When this machine is on then the ray falls on the printed bar & this light ray is reflected This ray is converted into the signals which is understable by the CPU Then database examine the incoming data & identify the products At last CPU shows result on monitor or print through special printer called `POS printer`

Pen Sometimes known as stylus. Can be used for writing and pointing. Writing is difficult.

Touch Screen Accept input by allowing the user to place a fingertip directly on the screen. Use Sensors. Many technology are used.