Presentation on theme: "MONITORS Known as a display screens. Monitors present visual images of text and graphics. Monitors vary in size, shape, and cost."— Presentation transcript:
MONITORS Known as a display screens. Monitors present visual images of text and graphics. Monitors vary in size, shape, and cost.
1. Monitor’s features The most important characteristic of a monitor is its clarity. Clarity refers to the quality and sharpness of the displayed images. i. Resolution - One of the most important features. - Images are formed on a monitor by a series of dots o pixels (picture elements).
-Resolution is expressed as a matrix of these dots or pixels. -For example many monitors today have a resolution: 1280 pixel for columns 1024 pixel rows Total = 1 310 720 pixels - The higher a monitor’s resolution the clearer the images produces.
ii. Dot Pitch -The distance between each pixel. -Most newer monitors have a dot pitch of.31 mm or less. -The lower the dot pitch (the shorter the distance between pixels) the clearer the images produced.
iii. Refresh rate -Indicates how often a displayed image is updated or redrawn on the monitor. -Most monitors operate at a rate of 75HZ, which means that the monitor is redrawn 75 times each second. -Images displayed on monitor s with refresh rates lower than 75 HZ appear to flicker and can cause eye strain. -The faster the refresh rate, the better the quality of images displayed.
iv. Size -Viewable size is measured by the diagonal length of a monitor’s viewing area. -Common sizes are 15, 17, 19 and 21 inches. -The smaller the monitor size the better the quality of images displayed.
3. Types of monitor a)Cathode-Ray tube (CRT) -The most common type of monitor for the office and the home. -These monitors are typically placed directly on the system unit or on the desktop. -CRT’s are similar in size and technology to televisions. -The advantages of CRT are low cost and excellent resolution. -The disadvantages is that they are bulky and occupy amount of space on the desktop.
b) Flat- Panel Monitor - Flat-panel monitors are easier to transport and portable monitor. -It much thinner and require less power to operate than CRTs. -These monitors are widely used with desktop, tablet PC and handheld computer.
Types of flat-panel monitor i. Passive matrix / dual-scan monitors -Create images by scanning the entire screen. -These type requires very little power, but the clarity of the images is not as sharp. ii. Active-matrix / thin film transistor (TFT) -This type do not scan down the screen, instead each pixel is independently activated. -They can display more colors with better clarity. -Active-matrix monitors are more expensive and require more power.
Other monitors c) Other monitors These monitors are used for more specialized applications, such as reading books, making presentations, and watching television. 1. E-book readers -Handheld, book-sized devices that display text and graphics. -Using content downloaded from the web or from special cartridges. -These devices are used to read newspapers, magazines, and entire books.
2. Data projectors -Specialized devices similar to slide projectors. -These devices, however, connect to microcomputers and project computer output just as it would appear on a monitor. -Data projectors are commonly used for presentations almost anywhere from the classroom to the boardroom.
3. High definition television (HDTV) -A recent development in the merger of microcomputers and television, called PC/TV. -HDTV delivers a much clearer and more detailed wide-screen picture than regular television. -Because the output is digital and users can readily freeze video sequences to create high-quality still images.