Input Devices

Input devices are objects that are used to communicate with computers. Although input devices may read text, numbers, images, audio, or video, all data is transformed to machine-readable form, or binary format, before being sent exclusively for processing. The computer has a variety of input devices that allow data to be entered into the system. Any machine that provides data into a computer is referred to as an input device. Alternate input devices are also used to refer to input devices other than keyboards. Aside from keyboards and mice, there are also lightpens and trackballs.

Some of the commonly used input devices are as follows:

Keyboard:

Because the first six keys on the top row of letters are Q, W, E, R, T, and Y, the arrangement of the letters is known as the QWERTY layout. Actually, the layout was created to prevent key jamming. In most computers, the keyboard serves as the primary input method. The main function of an alphanumeric keyboard is to enter long strings of characters. It has proven to be a useful tool for entering non-graphical data. Today's keyboards also come with capabilities that make menu selection or graphical operations easier. With only roughly 100 keys, it is a comparatively simple device that communicates with the CPU using a unique character code from each key press. Cursor control keys, function keys and numerical keypads are the common features on a general purpose keyboards. Some keyboards also include the cursor positioning devices such as a track ball or a joystick. The part of keyboard is similar to typewriter.

• All letters, numbers, punctuation marks, and modifier keys are included in alphanumeric keys. The keys for modifiers are shift, control, and alt.
• The right side of the keyboard typically houses the numerical keys, which have ten digits (0–9) and mathematical operations (+, –, *, /).
• The function keys are located at the top of the keyboard: F1, F2,... and so on. They make it possible to communicate with the computer without having to input lengthy sequences of text.
• You can move the cursor around the screen with the cursor movement keys.

Mouse:

The cursor or pointer's movement on a display screen is controlled by a mouse, which is a straightforward pointing (input) device. It is a portable gadget that can be moved over a smooth surface to activate the cursor movement on a screen. You can roll it around a firm, flat surface because it is a little object. The mouse pointer goes in the same direction as the cursor on the screen when you move the mouse. To select text, access menus, move files, or interact with other programs, files, or data displayed on the screen, one uses a pointer, which is typically an arrow. It allowed users to swiftly and simply move the cursor wherever on the screen without having to use the cursor movement buttons. A mouse allows user to create graphic elements on the screen such as lines, curves & freehand shapes.

Types of mouse:

• Mechanical Mouse
• Optical Mouse

Scanner:

The information is captured by a scanner, which is an input device, and is then stored in visual format for presentation on a graphical screen. It has two parts: the first illuminates the page so that the optical picture may be recorded, and the second transforms the optical image into digital format for computer storage.

 Types of scanner:

• Portable and less priced hand-held scanners must make many passes over a single page since they are not as wide as letter-size paper.
• Scanners with flatbeds cost more, but they can scan a page in a single pass.

Microphone:

A microphone is a crucial voice input tool. It is utilized to input commands and audio data into a computer system. Recognition of human voice or speech for direct computer input is one of the most fascinating fields of research. As a result, it is also known as a voice recognition unit. The tiniest individual sounds in a language, known as phonemes, are translated into text or documents by voice recognition software. Even computer programs exist that can translate across languages, for example, from English to Japanese. There are two different types of voice recognition systems: discrete speech and continuous speech. With this method, data entry will not be required, and computer use will be made simple for the user. The three most common types are described below:

• Dynamic: The most popular kind of microphones are dynamic ones. They feature a straightforward construction that incorporates a magnet that is enclosed in a metal coil.
• Condenser: For audio recording, condenser microphones are frequently employed. They are renowned for their flat frequency response and sensitivity.
• Ribbon: Ribbon microphones are renowned for having a high level of fidelity. They have an aluminum ribbon inside that is very thin and suspended in a magnetic field.

Touch Screen:

The user can use a touch screen to point directly at the computer screen and often choose from a menu of options. The majority of touch screen computers have sensors within or close to them that can recognize a finger contact. They are frequently used in supermarkets, drugstores, department stores, and other establishments. The various touch screen models are:

• Optical Touch Panel
• Resistive Touch Panel
• Acoustical Touch Panel
• Capacitive Touch Panel

Optical Bar Code Reader (OBR):

It is an input device that searches a collection of vertical bars of various widths for certain information. This is used to read tags on store products, books from the library, medical records, and other items. The product is identified by the bar code to the server computer, which also holds the product's description and the most recent price. It's a portable device. The barcode reader is a unique kind of scanner. Like any other scanner, it works by projecting light onto the printed image—the barcode—and measuring the intensity of the light's reflection at various points on the image.

Optical Mark Recognition (OMR):

Many schools and colleges use it as an input device to read the answer sheets that are on the specific sheet of paper and send the information to a computer for processing. It can detect markings on computer-readable papers. Even though specialized OMR readers are needed to read data from OMR forms, individuals filling out the information only need a black pen.

Magnetic Ink Character Recognition (MICR):

It is an input tool that is utilized for character recognition. It is frequently used in banks to read checks with magnetic ink used to write all the information. It enables the computer to read characters that were printed with magnetic ink for data entry. This equipment is designed specifically to read magnetic strips. Magnetic strip technology is also utilized in ATMs, debit and credit cards, as well as on ID cards for schools and institutions.

Webcam:

A webcam is a camera that is somehow linked to the Internet or the World Wide Web. Webcams are capable of capturing a wide variety of photos in various formats. Personal cameras that are connected to a home computer are one of the most popular kinds of webcams. With the aid of appropriate software, users can share a moving image of themselves with others. Most cameras make an effort to be accessible around-the-clock. The visual quality might not always be excellent.