2. KEYBOARD ENTRY One of the most common ways to input data is by keyboard . It translate numbers, letters, and special characters that people understand into electrical signals. There are a wide variety of different keyboard designs. The most common types are: Traditional keyboards , Flexible keyboard , Ergonomic keyboard , Wireless keyboard , PDA keyboard COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
3. Traditional keyboard Full-sized, rigid, rectangular keyboards that include function, navigational, and numeric keys. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
4. Flexible keyboard Fold or roll up for easy packing or storage. They are designed to provide mobile users with a full-sized keyboard with minimal storage requirements. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
5. Ergonomic keyboard Similar to traditional keyboard. The keyboard arrangement, however, is not rectangular and a palm rest is provided. They are designed specifically to alleviate wrist strain associated with the repetitive movements of typing. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
6. Wireless keyboard Transmit input to the system unit through the air. By eliminating connecting wires to the system unit, these keyboards provide greater flexibility and convenience. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
7. PDA keyboard Miniature keyboards for PDA’s for sending email, creating documents and more. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
8. FEATURES A computer keyboard combines a typewriter keyboard with a numeric keypad , used to enter numbers and arithmetic symbols. It also has many special purpose keys. Some keys such as the Caps Lock key are toggle keys . These keys turn a feature on or off. Other such as Ctrl key are combination keys , which perform an action when held down in combination with another key. (See Figure 7-4) COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
9. POINTING DEVICES Pointing , of course, is one of the most natural of all human gestures. Pointing devices provide a comfortable interface with the system unit, by accepting pointing gestures and converting them into machine-readable input. There are a wide variety of different pointing devices including the mouse , joystick , touch screen , light pen and stylus . COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
10. MOUSE A mouse controls a pointer that is displayed on the monitor. The mouse pointer usually appears in the shape of an arrow. It frequently changes shape, however, depending on the application. A mouse can have one, two, or more buttons, which are used to select command options and to control the mouse pointer on the monitor . The three basic designs of mouse are mechanical , optical and cordless or wireless mouse . COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
11. Mechanical mouse Mechanical mouse is generally considered the traditional type and is currently the most widely used. It has a ball on the bottom and is attached with a cord to the system unit. As you move the mouse across a smooth surface, or mouse pad , the roller rotates and controls the pointer on the screen. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
12. Optical mouse Optical mouse has no moving parts. It emits and senses light to detect mouse movement. The newer type of mouse has some advantages compared to the mechanical mouse: it can be used on any surface, is more precise, and does not require periodic cleaning. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
13. Cordless or wireless mouse Cordless or wireless mouse is a battery-powered device that typically uses radio waves or infrared light waves to communicate with the system unit. This devices eliminate the mouse cord and free up desk space. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
14. It is an upside-down version of the mouse. A ball mounted in a box is rolled with the fingers to move the cursor. Some people prefer the trackball over the mouse because the trackball does not require as much hand-eye coordination, nor does it require the extra desk space to move the mouse pointer. It is usually included in portable computers such as laptops. TRACKBALL COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
15. A joystick is the most popular input device for computer games. You control a game actions by varying the pressure, speed, and direction of the joystick. Additional controls such as buttons and triggers are used to specify commands or initiate specific actions. JOYSTICK COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
16. A touch screen is a particular kind of monitor with a clear plastic outer layer. Behind this layer are criss-crossed invisible beams of infrared light. TOUCH SCREEN This arrangement enables someone to select actions or commands by touching the screen with a finger. Touch screens are easy to use, especially when people need information quickly. They are commonly used at restaurants, ATM, and information centers. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
17. LIGHT PEN A light pen is a light-sensitive pen-like device. The light pen is placed against the monitor. This closes a photoelectric circuit and identifies the spot for entering or modifying data. For example, light pens are used to edit digital images. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
18. SCANNING DEVICES Scanners move across text and images. Scanning devices convert scanned text and images into a form that the system unit can process. There are three type of scanning devices: Optical scanners , Bar code readers , and Character and Mark recognition devices . COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
19. OPTICAL SCANNER An optical scanner , also known as a scanner , accepts documents consisting of text and/or images and converts them to machine readable form. There are two types of scanners: flatbed and portable scanner . Flatbed scanner Portable scanner COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
20. BAR CODE READERS These devices are either handheld wand readers or platform scanners . They contain photoelectric cells that scan or read bar codes , or the vertical zebra-striped marks printed on product containers. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
21. CHARACTER & MARK RECOGNITION DEVICES Character and mark recognition devices are scanners that are able to recognize special characters and marks. They are specialty devices that are essentials tools for certain applications. Three types are: Magnetic-ink character recognition (MICR), Optical-character recognition (OCR), Optical-mark recognition (OMR). COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
22. Magnetic-ink character recognition (MICR) Used by banks to automatically read those unusual numbers on the bottom of checks and deposit slips. A special purpose machine known as reader/sorter reads these numbers and provides input that allows banks to efficiently maintain customer account balances. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
23. Optical-character recognition (OCR) Uses special preprinted characters that can be read by a light source and changed into machine-readable code. A common OCR device is the handheld wand reader . These are used in department stores to read retail price tags by reflecting light on the printed characters. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
24. Optical-mark recognition (OMR) Also called mark sensing . An OMR device senses the presence or absence of a mark, such as a pencil mark, OMR is often used to score multiple-choice tests such as the College Board’s Scholastic Aptitude Test (SAT) and Graduate Record Examination (GRE). COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
25. IMAGE CAPTURING DEVICE Optical Scanners, like traditional copy machines, can make a copy from an original. For example, an optical scanner can make a digital copy of a photograph. Image capturing devices , on the other hand, create or capture original images. These devices include digital cameras and digital video cameras COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
26. DIGITAL CAMERA Digital cameras are similar to traditional cameras except that images are recorded digitally on a disk or in the camera’s memory rather than on a film, and downloaded , or transferred, to your computer. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
27. DIGITAL VIDEO CAMERA Unlike traditional video cameras, digital video cameras record motion digitally on a disk or in the camera’s memory. Most have the capability to take still images as well. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
28. DIGITIZING DEVICES Digitizing devices convert a sketch or figure into a form that can be processed by a computer. Similar to slate tablet PCs, these devices have some type of flat surface and a writing device. As the user moves the writing device across the surface, the digitizing device records the movement as a series of points and sends this information to the computer. Two widely used digitizing devices are graphics tablets and digital notebooks . COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
29. GRAPHICS TABLET Graphics tablet use a special graphics surface or tablet and s special stylus or pen-like device. The user either directly sketches on the tablet or traces images that have been placed on the tablet. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
30. DIGITAL NOTEPADS Digital notepads are similar to tablet PCs except that they typically use regular notepads and pens. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
31. AUDIO INPUT DEVICES Audio input devices convert sounds into a form that can be processed by the system unit. By far the most widely used audio input device is the microphone . Audio input can take many forms including human voice and music. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
32. VOICE Voice recognition systems use a microphone, sound card, and special software. These systems allow users to operate computers and to create documents using voice commands. Portable voice recognition systems are widely used by doctors, lawyers, and others to record dictation. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
33. Two types of voice recognition systems: Discrete-speech recognition systems are able to recognize individual word based on their sound. Continuous-speech recognition systems are able to distinguish between same-sounding words by evaluating the context within which individual words are used. COMPUTER CONCEPTS AND FUNDAMENTALS INPUT & OUTPUT DEVICES
