Transcript Basic English for Computing - u
Basic English for Computing
Types of Monitors
What is Monitor ?
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The main output device Another term for display screen. The term monitor, however, usually refers to the entire box, whereas display screen can mean just the screen. In addition, the term monitor often implies graphics capabilities
How Many Colors are Abled to Display?
Six Types of Monitors
1-bit black & white display 4-bit 16 color display 8-bit 256 color display 16-bit Hi Color display 24-bit True Color display 32-bit True Color display
1-bit Black & White Display
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There are only two colors Code 1 means „black” Code 0 means „white”
8-bit 256 Color Display
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Each color has an 8 bit code, from 0 to 255 Code 0 means „black” Code 255 means „white”
24-bit True Color Display
• Each color has a 24-bit code • Each color made from blue, green & red. The components blue, green & red all have an 8-bit code
Two Types of Monitors
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Displays come in a few different types. A standard CRT is the most common type of monitor and widely used. They are also the most cost-effective. LCD and TFT monitors have a flat tube so they take up less desk space. They are more expensive than CRTs, but have recently dropped in price
CRT (Cathode Ray Tube) LCD (Liquid Crystal Display)
CRT Monitors
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A CRT is a vacuum tube, the same picture tube designed into typical television sets. The internal cathode fires electron beams at phosphor dots onto the inside of the glass tube. The phosphors in your CRT are chemicals that emit red, green, or blue light when struck by electrons The most prevalent type of monitor today is the cathode ray tube (CRT). Despite its rather sci-fi sounding name, a CRT is the same as the picture tube inside your TV. They work by firing beams of electrons at phosphor dots on the inside of a glass tube. The phosphors in a CRT are chemicals that emit red, green or blue light when hit by electrons. These monitors are capable of multiple resolutions, give the best look to full-motion video and provide better control over colour calibration for graphic artists
LCD Monitors
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In LCD screens, however, each pixel's produced by a very small cell containing liquid crystals, and the rod shaped molecules bend light responding to an electrical current In the opposing corner are flat panel displays or LCDs (liquid crystal displays) commonly used in laptops and fast becoming popular as desktop monitors. Their major selling points are a slim profile and light weight. In the screen of a LCD monitor, each pixel is produced by a tiny cell which contains a thin layer of liquid crystals. These rod shaped molecules bend light in response to an electric current. It's the same display technology that resides in your digital watch but more sophisticated
CRT vs LCD
Physical Size
• One of the biggest advantages of LCD monitors is that they are compact and lightweight. An LCD monitor is based upon a very thin screen as opposed to the bulky tube of a CRT monitor. This means that not only do they take up less of your desktop space, they can also be used in many places where a larger CRT monitor can not fit. Shown here, a 12.1" LCD monitor with a stand takes up only about one-third of the desk space of a typical 14" CRT monitor
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CRT vs LCD
Display Size
Thanks to advances in LCD technology, color flat panel LCD monitors are now available that are comparable in screen size to traditional CRT monitors. Shown here, a 12.1" LCD display (left) has only a slightly smaller viewing area than a typical 14" CRT monitor. Newer, larger LCD monitors are also appearing that have 15", 17", and even larger screen sizes that are comparable to the largest CRT monitors. One thing to note is that LCD monitors are typically sized by their actual viewable diagonal measurement, but CRTs typically are not. For example, the viewable area on a 17" LCD monitor will typically measure 17" diagonally, but the viewable area on a CRT monitor will typically only measure 16" diagonally
CRT vs LCD
Viewing Angle
• Another issue with the LCD monitor is the viewing angle. A CRT screen can be looked at from a very wide angle, practically from the side, but an LCD monitor typically has a smaller viewing angle, needing to be viewed more directly from the front. From the side, the image on an LCD screen can seem to disappear, or invert colors. Newer displays that are coming out have wider viewing angles so this is not as much of an issue as it has been in the past
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CRT vs LCD
Resolution
An important issue with LCD monitors is resolution. CRT monitors are usually capable of displaying multiple video resolutions, each with the same quality. LCD monitors, however, usually has what is called a Native resolution, or the resolution that it displays best. The native resolution is generally the highest resolution that the LCD can display and this is the display resolution that will appear the crispest/sharpest
Power Consumption and Radiation Emission
Besides being compact and space saving, LCD displays offer several other benefits. For one, LCD monitors consume much less energy than CRT monitors. This makes the LCD great for laptop and portable computers. Secondly, CRT monitors are known to emit harmful radiation, whereas LCD monitors do not
Price
CRT monitors are generally more affordable than LCD monitors. In the past LCD monitors have been very expensive but their costs have come down quite a bit in the last 1-2 years. One thing to consider is the up-front cost versus the long-term cost. A CRT monitor will cost less up front but will use more energy than a flat panel monitor. An LCD monitor will cost more up front but will conserve energy in the long run. The energy savings may not be much for an individual user, but if you are looking at a corporate office where 50 displays are in use, the energy savings might be more of an issue
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Video Resolutions
Screen real estate is usually measured in pixels. The more pixels your screen displays, the more stuff you can cram onscreen. Of course, as you pack more pixels into the same area, all those pixels get smaller The following settings have an aspect ratio of 4:3
VGA 640 x 480 SVGA 800 x 600 XGA QVGA SXGA+ 1024 x 768 1280 x 960 1400 x 1050 UXGA QXGA QSXGA+ 1600 x 1200 2048 x 1536 2800 x 2100 QUXGA 3200 x 2400
The following settings with either a 5:4 or 16:9 ratio
WXGA 1280 x 800 SXGA WSXGA+ WUXGA QSXGA 1280 x 1024 1680 x 1050 1920 x 1200 2560 x 2048
What are Pixels?
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Pixels are dots used to display an image on a screen or printed matter, the little glowing spots on a computer screen that make up the display. The word pixel is a blend of the words picture and element. Usually the term refers to pixels in a digital context, but it is often more generalized to refer to any smallest unit of an image While pixels are the smallest complete element of an image, they are comprised of even smaller elements. In a standard RGB monitor, for example, each pixel has three dots within it: a red, blue, and green dot. In theory these dots all converge at the same point, making them visibly seamless, but in practice some fuzziness is often apparent. The measure of total pixels in an image is referred to as its resolution, and the higher the resolution in a small area, the more difficult it is to distinguish between individual pixels