Information and Communications Technology (ICT) Lecture PDF

Information and Communications Technology (ICT) Dr. AHMED HAMDY ABU-ELKASEM 1 Lecture_6 Outlines 1.KEYBOARDS 2.POINTING AND TOUCH DEVICES 3.SCANNERS, READERS, AND DIGITAL CAMERAS 4.AUDIO INPUT 5.DISPLAY DEVICES 6.PRINTERS 7.AUDIO OUTPUT 2 1. KE...

Information and Communications Technology (ICT) Dr. AHMED HAMDY ABU-ELKASEM 1 Lecture_6 Outlines 1.KEYBOARDS 2.POINTING AND TOUCH DEVICES 3.SCANNERS, READERS, AND DIGITAL CAMERAS 4.AUDIO INPUT 5.DISPLAY DEVICES 6.PRINTERS 7.AUDIO OUTPUT 2 1. KEYBOARDS keyboard—a device used to enter characters at the location on the screen marked by the insertion point or cursor. Keyboards can be built into a device, attached by inserting the keyboard’s wired cable or wireless receiver into a USB port. To allow individuals to work under a variety of lighting conditions, keyboards today are increasingly using illuminated keys to light up the characters on the keyboard. In addition, some keyboards are made for languages other than English and some keyboards are designed for special purposes, such as to allow easy input for specific systems. 3 1. KEYBOARDS 4 1. KEYBOARDS 5  2. POINTING AND TOUCH DEVICES Mice As it moves, an on-screen mouse pointer—usually an arrow—moves accordingly. Older mechanical mice have a ball exposed on the bottom surface of the mouse to control the pointer movement. Most mice today are optical mice or laser mice that track movements with light. In addition to being used with desktop computers, mice can also be used with portable computers if an appropriate port is available, or the mouse can connect via Bluetooth. 6 2. POINTING AND TOUCH DEVICES Pens / Styluses Many devices today can accept pen input; that is, input by writing, drawing, or tapping on the screen with a pen-like device called a stylus. Sometimes, the stylus is simply a plastic device with no additional functionality; other times, it is a pressure sensitive device that transmits the pressure applied by the user to the device that the stylus is being used with to allow more precise input. 7 2. POINTING AND TOUCH DEVICES Depending on the software being used, handwritten input be stored as handwritten characters that can be recognized by the computer, or be converted to editable, typed text. software with handwriting recognition capabilities must be used. The use of handwriting recognition technology in conjunction with digital forms saves time, reduces paper waste, and increases data accuracy. 8  2. POINTING AND TOUCH DEVICES A graphics tablet—also called a pen tablet or digitizing tablet—is a flat, touch- sensitive tablet used in conjunction with a digital pen. Graphic artists, photographers, and other graphics professionals often use graphics tablets in conjunction with image editing software to create original images or to modify digital photographs. 9  2. POINTING AND TOUCH DEVICES Touch Screens Touch screens allow the user to touch the screen with finger to select commands or provide input to the computer. Touch screens are common on portable computers, smartphones and other mobile devices to provide easy input. Many touch screens today are multi-touch; that is, they can recognize input from more than one finger at a time. Touch screens are also used in consumer kiosks, restaurant order systems, and other point-of-sale (POS) systems. 10 2. POINTING AND TOUCH DEVICES Other Pointing Devices Gaming Devices A variety of gaming devices today controllers to supply input to a computer. Touch Pads are the most common pointing device for notebook and netbook computers. They are used to point to and select objects, to scroll through documents or other content, and to perform gestures such as swiping and pinching. 11 3. SCANNERS, READERS, AND DIGITAL CAMERAS are designed to capture data in digital form so computer can manipulate it. Some devices (as scanners and readers) convert data that already exists in physical form (such as on source documents like photographs, checks, or product labels); other devices (as digital cameras) capture data initially in digital form. Source data automation is widely used today because it can save a great deal of time and is much more accurate than recording the data on paper and then later entering it into a computer via a keyboard. 12 3. SCANNERS, READERS, AND DIGITAL CAMERAS Scanners A scanner captures an image of an object (usually a flat object) in digital form, and then transfers that data to a computer. The text in the scanned image, however, cannot be edited unless optical character recognition (OCR) software is used Optical character recognition OCR refers to the ability of a computer to recognize text characters printed on a document Flatbed scanners are designed to scan flat objects one page at a time. Portable scanners are designed to capture text and other data while on the go. Some are full page portable scanners others are handheld scanners. The quality of scanned images is indicated by optical resolution, usually measured in the number of dots per inch (dpi). Scanners today usually scan at between 2,400 × 2,400 dpi and 4,800 × 9,600 dpi. A higher resolution results in a better image but also results in a larger file size. 13 3. SCANNERS, READERS, AND DIGITAL CAMERAS Scanners 14 3. SCANNERS, READERS, AND DIGITAL CAMERAS Readers Readers are available to read the different types of codes and marks used today Barcode Readers A barcode is an optical code that represents data with bars of varying widths or heights. the most familiar barcodes are UPC (Universal Product Code), and ISBN (International Standard Book Number). A newer barcode designed for small consumer goods like fresh foods and jewelry is the Data Bar. Newer two-dimensional (2D) barcodes store information both horizontally and vertically and can hold significantly more data. One of the most common 2D barcodes—the QR (Quick Response) code that represents data with a matrix of small squares. Barcodes are read with barcode readers. 15 most smartphones and media tablets today have barcode reading capabilities. 3. SCANNERS, READERS, AND DIGITAL CAMERAS Readers 16 3. SCANNERS, READERS, AND DIGITAL CAMERAS Readers Biometric Readers Biometrics is the science of identifying individuals based on measurable biological characteristics. Biometric readers are used to read biometric data about a person so that the individual’s identity can be verified based on a particular unique physiological characteristic (such as a fingerprint or a face) or personal trait (such as a voice or a signature). 17 3. SCANNERS, READERS, AND DIGITAL CAMERAS Digital Cameras Digital cameras are usually designated either as still cameras (which take individual still photos) or video cameras (which capture moving video images), although many cameras today take both still images and video. In addition to stand-alone still and video cameras, digital camera capabilities are integrated into many portable computers and mobile devices today. 18  4. AUDIO INPUT Voice Input and Speech Recognition Systems Voice input—inputting spoken words and converting them to digital form typically performed via a microphone or headset. It can be used in conjunction with sound recorder software to store the voice in an audio file, It can also be used in conjunction with speech recognition software to provide spoken instructions to a computer. Speech recognition systems enable the computer to recognize voice input as spoken words. 19  5. DISPLAY DEVICES Display Device Characteristics 1. Display devices can be monochrome displays (in which each pixel can only be one of two colors, such as black or white) or color displays (in which each pixel can display a combination of three colors—red, green, and blue—to display a large range of colors). 2. Display devices can be CRT monitor (use cathode-ray tube technology) or thinner and lighter flat panel displays. 3. Display device size is measured diagonally from corner to corner. 4. Display device is divided into a fine grid of tiny pixels. The number of pixels used on a display screen determines the screen resolution. 20  5. DISPLAY DEVICES Wearable Displays A wearable display usually projects the image from a mobile device (such as a smartphone or media tablet) to a display screen built into the glasses via a wireless connection. In addition to consumer wearable displays that have entertainment and productivity applications, there are also wearable displays designed for soldiers and other mobile workers. 21  5. DISPLAY DEVICES Flat-Panel Display Technologies The most common flat-panel technologies include liquid crystal display (LCD), various types of light emitting diode (LED), and gas plasma. Data and Multimedia Projector A data projector is used to display output from a computer to a wall or projection screen. 22 6. PRINTERS Printers produce images through either impact or nonimpact technologies. Impact printers, like old ribbon typewriters, have a print mechanism that strikes the paper to transfer ink to the paper. For example, a dot-matrix printer. Most printers today are nonimpact printers, meaning they form images without the print mechanism touching the paper. Nonimpact printers usually produce higher quality images and are much quieter than impact printers are. The most common types of printers today—laser printers. 23 6. PRINTERS Color vs. Black and White Both color printers and black-and-white printers are available. Color printers use cyan (blue), magenta (red), and yellow ink or toner. Color printers either apply all the colors in one pass or go through the entire printing process multiple times, applying one color during each pass. Print Resolution The number of dots per inch (dpi)—called the print resolution—affects the quality of the printed output. Printers with a higher print resolution tend to produce sharper text and images than printers with a lower resolution tend to produce. Print Speed Print speed is typically measured in pages per minute (ppm). 24 6. PRINTERS Multifunction Capabilities Some printers today offer more than just printing capabilities. These units—referred to as multifunction devices (MFDs) or all-in-ones— typically copy, scan, fax, and print documents. MFDs can be available as both color and black- and-white devices 25  6. PRINTERS Ink-Jet Printers Ink-jet printers form images by spraying tiny drops of liquid ink from one or more ink cartridges onto the page, one printed line at a time. With the use of special photo paper, ink-jet printers can also print photograph- quality digital photos. 26 6. PRINTERS Special-Purpose Printers 27  7. AUDIO OUTPUT Computer speakers, the most common type of audio output device. Portable computers and mobile devices have speakers integrated into the device. Headsets are headphones with a built-in microphone and are often used when dictating, making phone calls, or participating in Web conferences using a computer. wireless headsets are commonly used in conjunction with mobile phones. Even smaller than headphones are the earphones and earbuds often used with portable digital media players, handheld gaming devices, and other mobile devices. 28