What are Input Devices?
The electromagnetic devices that accept data or a set of instructions from the outside world and then translate that data into machine-readable and understandable form are known as input devices. Computer input devices serve as an interface between the outside world and the computer for proper communication. When the users enter data using various input devices, the data can be saved in computer memory for further processing and preparation. Using the output devices, the intended and calculated results can be acquired when the processing and handling are completed. An input device transmits data to a computer and allows you to communicate with it and control it.
Different Input Devices
1. Keyboard: For entering data into a computer, the keyboard is the most common and commonly used input device. It contains various keys for entering letters, numbers, characters. Although there are some additional keys for completing various activities, the keyboard layout is identical to that of a standard typewriter. It is generally available in two different sizes: 84 keys or 101/102 keys and for Windows and the Internet, it is also available with 104 keys or 108 keys. It is connected to a computer system with the help of a USB or a Bluetooth device.
The keys on the keyboard are:
- Numeric Keys: These keys are used to enter numeric data and move the cursor. It is typically made up of 17 keys.
- Keyboard Shortcuts: These keys include the letter keys (A-Z) and the number keys (09).
- Control Keys: The pointer and the screen are controlled by these keys. It comes with four directional arrow keys. Control keys include Home, End, Insert, Alternate(Alt), Delete, Control(Ctrl), and Escape.
- Special Keys: Enter, Shift, Caps Lock, NumLk, Tab, and Print Screen are some of the special function keys on the keyboard.
- Function Keys: The 12 keys from F1 to F12 are on the topmost row of the keyboard.
Type of keyboard:
Generally, the keyboard is of three types:
- QWERTY Keyboard
- AZERTY Keyboard
- DVORAK Keyboard
Characteristics of Keyboard :
- The keyboard has various functions keys for a different purpose
- Instead of using the mouse, we can utilize the arrow keys on the keyboard to do the same purpose as the mouse.
- The main keyboard, cursor keys, numeric keypad, and function keys are the four primary components of a keyboard.
- Keyboards are more affordable.
2. Mouse: The mouse is the most used pointing device. While clicking and dragging, the mouse moves a little cursor across the screen. If you let off of the mouse, the cursor will come to a halt. You must move the mouse for the computer to move; it will not move on its own. As a result, it’s a device that accepts input. Or we can say that a mouse is an input device that allows you to control the coordinates and movement of the on-screen cursor/pointer by moving the mouse on a flat surface. The left mouse button can be used to pick or move items, while the right mouse button displays additional menus when clicked. It was invented in 1963 by Douglas C. Engelbart.
Types of mouse:
Generally, the mouse is of four types:
- Trackball Mouse
- Mechanical Mouse
- Optical Mouse
- Wireless Mouse
Characteristics of the mouse:
- A mouse is used to move the cursor on the screen in the desired direction.
- A mouse allows users to choose files, folders, or multiple files or text or, all at once.
- Hover over any object with the mouse pointer.
- A mouse can be used to open a file, folder, etc. You must first move your pointer to a file, folder, and then double-click on it to open or execute.
3. Joystick: A pointing device used to move the cursor around the screen is the joystick. Both the bottom and top ends of the stick have a spherical ball affixed to them. A socket contains the lower spherical ball. You can adjust the joystick in all directions. Trackballs became quite popular in laptops and PCs since they fit neatly inside the case and take up less room when in use. They are more precise and long-lasting than a mouse, which is why they are still utilized. It is invented by C.B.Mirick.
Characteristics of Joystick:
- It’s utilized to regulate the cursor’s position across a display screen.
- It’s utilized in computer games to move the characters and symbols around.
- It commonly features one or more push buttons, the condition of which can be controlled by the computer as well.
4. Light Pen: A light pen is a pointing device that has the appearance of a pen. It can be used to draw on the monitor screen or to pick a menu item. In a small tube, a photocell and an optical system are housed. The photocell sensor element determines the screen location and sends a signal to the CPU when the tip of a light pen is moved across a monitor screen while the pen button is pressed.
Characteristics of the light pen:
- When drawing graphics, a light pen comes in very handy.
- Objects on the display screen are selected with a light pen.
5. Scanner: A scanner is a type of input device that works in the same way as a photocopier. It’s used when there’s data on paper that needs to be transferred to the computer’s hard disc for further processing. The scanner collects images from the source and translates them to a digital version that can be saved on the hard disks. These graphics can be changed before they are printed.
Types of Scanner:
Generally, the scanner is of five types:
- Flatbed Scanner
- Handheld Scanner
- Sheetfed Scanner
- Drum Scanner
- Photo Scanner
Characteristics of Scanner:
- You can scan film negatives via a scanner if there is a transparent media adaptor.
- A scanner may also scan low-quality or non-standard-weight paper.
- The scanners are adaptable, allowing you to scan a wide range of items regardless of their size. You can scan small items as well as large documents if you can locate them.
6. OCR: OCR stands for “Optical Character Recognition” in its full form. OCR is a computer reading technique that reads numbers, characters, and symbols. OCR is a technique for recognizing text in documents that have been scanned into digital form. Optical character recognition (OCR) refers to a device that reads printed text. Character by character, OCR scans the text, converts it to a machine-readable code, and saves it into the memory of the system. OCR also functions as a scanner, scanning documents, photos, images, and handwritten text and storing the information in memory, which may then be compared to previously stored data.
Characteristics of OCR:
- The technology offers a complete solution for form processing and document capture.
- It has capabilities for defining shapes, scanning, image pre-processing, and identification.
7. Barcode Reader: A bar code reader is a device that reads bar-coded data (data that is represented by light and dark lines). To label things, number books, and so on, bar-coded data is often utilized. It could be a standalone scanner or a component of one. A barcode reader is a device that reads barcodes and extracts data from them. The code bar is used to read the bar code printed on any goods. By impacting light beams on barcode lines, a barcode reader identifies existing data in barcodes.
Characteristics of Barcode Reader:
- When a card is inserted, auto-start barcode scanners begin scanning immediately.
- Reading indicators give the user confirms that the card has been swiped correctly.
- It’s simple to use, simply hold your phone up to the code and scan it.
8. Web Camera: A webcam is an input device since it records a video image of the scene in front of it. It can either be incorporated inside the computer (for example, a laptop) or connected via USB. A webcam is a small digital video camera that is connected to a computer. Because it can capture pictures and record video, it’s also known as a web camera.
Characteristics of Web Camera:
- Webcams are used to allow individuals to see one other while chatting online. This is formally referred to as ‘teleconferencing’.
- Because webcams can take a picture only if movement is detected in the scene in front of them, they are commonly utilized in burglar alarms and other security systems.
- Hundreds of webcams can be found all around the world, each pointing to a fascinating scene such as the exterior view of a facility in the Arctic or Niagara Falls. The webcam is connected to a computer that regularly sends an image to an internet server. After that, people connect to the server to view the most recent image.
9. Graphic Tablet: A graphics tablet, also known as a digitizing tablet, is a computer input device that allows users to draw drawings and graphics by hand, much like they would with a pencil and paper. A graphics tablet is a flat surface on which the user can “draw” a picture with the help of an attached stylus, which is a pen-like drawing device.
Characteristics of a Graphics Tablet:
- The graphics tablet is a pressure-sensitive tablet that is controlled by a pen.
- Drawing, writing, inserting, etc. can be done with the pen.
- It provides more precision and the ability to monitor (than a touchscreen).
10. Digital Camera: Digital camera is a device that takes photographs as input. Images are saved on memory cards as data. It comes with an LCD display that allows users to view and review photographs. A digital camera contains photosensors that record the light that enters into the camera lens. So, when the light strikes the photosensors, they return the electric current and this electric current is used to create images.
Characteristics of Digital Camera:
- Users can immediately examine images and movies on the LCD screen.
- All the photos can be stored in the storage device.
- Users can select and choose the images they want to develop.
- Easily portable & takes less space.
Question 1. List disadvantages of the LCD monitor.
The disadvantages of LCD monitor are :
- When the temperature is high the contrast is a decreases.
- The color and contrast of LCD monitor are depending on the viewing angle.
- LCD monitor uses more energy and generate more heat
- It contains individual liquid crystals and they are unable to complete all blocks of the backlight.
- LCD monitor is bright, but not much bright for really bright settings.
Question 2. A device that rolls about on a desk and controls the position of the cursor on the screen is?
Question 3. __________ is a device that converts handwritten impressions into coded text and positional information for computer input.
Question 4. Which keys are present on the keyboard at the topmost row?
Function keys from F1 to F12.
Question 5. With light source, OCR recognizes what?
The shape of the characters is recognized with help of a light sources by OCR.