An input device is used to supply data to the computer.
They are given below:
1. Key board:
It is the most widely used device to input information in the form of words, numbers etc. There are 101 keys on a standard key board. The keys on the key board are often classified into alpha numeric keys (A to Z, Oto 9), function keys (F1 to F12), special purpose keys (Special characters), cursor movement keys (arrow keys). While pressing a key, the corresponding code’s signal is transmitted to the computer.
2. Mouse:
It is a pointing device, that controls the movement of the cursor, or pointer as a display screen. A mouse has two or three buttons, it is often used in GUI oriented computers. Under the mouse there is a ball, when the mouse moves on a flat surface this ball also moves. This mechanical motion is converted into digital values that represents x and y values of the mouse movement.
3. Optical Mark Reader (OMR):
This device identifies the presence or absence of a pen or pencil mark. It is used to evaluate objective type exams. In this method special preprinted forms re- designed with circles can be marked with dark pencil or ink.
A high intensity beam in the OMR converts this into computer usable form and detects the number and location of the pencil marks. By using this we can evaluate easily and reduce the errors.
4. Bar code / Quick Response (QR) code reader:
Light and dark bars are used to record item name, code and price is called Bar Code. This information can be read and input into a computer quickly without errors using Bar Code Readers.
It consists of a photo electric scanner and it is used in super market, jewellery, textiles etc. QR codes are similar to barcodes but it uses two dimensional instead of single dimensional used in Barcode.
5. Joy Stick:
It is a device that lets the user move an object quickly on the screen. It has a liver that moves in all directions and controls the pointer or object. It is used for computer games and CAD / CAM systems.
6. Light Pen:
It is an input device that use a light sensitive detector to select objects directly on a display screen using a pen. Light pen has a photocell placed in a small tube. By using light pen, we can locate the exact position on the screen.
7. Scanner:
It is used to read text or pictures printed on paper and translate the information into computer usable form. It is just like a photostat machine but it gives information to the computer.
8. Digital Camera:
By using digital camera, we can take photographs and store in a computer. Therefore we can reduce the use of film. Hence it is economical.
9. Touchpad:
It is a pointing device found on the portable computers(laptop). Just like a mouse it consists of two buttons below the touch surface to do the operations like left click and right click. By using our fingers we can easily operate.
10. Microphone:
By using this device we can convert voice signals into digital form.
11. Biometric sensor:
It is used to read unique human physical features like fingerprints, retina, iris pattern, facial expressions etc. Most of you give these data to the Government for Aadhaar.
12. Smart card reader:
A plastic card(maybe like your ATM card) stores and transmit data with the help of a reader.
13. Digital Camera :
By using digital camera, we can take photographs and store in a computer. Therefore we can reduce the use of film. Hence it is economical.
