Types Of Moniter
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Types Of Moniter as PDF for free.
More details
- Words: 1,413
- Pages: 17
Types of Monitors
Monitors • The monitor is the most commonly used output device of most PCs. • Image quality is determined by two devices – Monitor – Video Controller.
Categories of monitors • Monochrome monitors – Can display only one color (Red or Green or Blue) against a contrasting background – Used for text only display
• Grayscale monitors – Display varying intensities of grey
• Color monitors – Can display between 16 colors to 16 million colors.
CRT (Cathode Ray Tube) Monitor • • • •
• • •
CRT technology, computer monitors continue to be referred to as "The Tube". A CRT works by moving an electron beam back and forth across the back of the screen. Electron beam is fired by an electron gun. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby enlightening the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen full of images. The smallest number of phosphor dots that the gun can focus on is called pixel (also called picture element. In colour monitors there are three colour beams Red, Green, Blue
Liquid Crystal Display (LCD) • A Liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. • It uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices. • LCD technology makes use of a liquid crystal solution that are present in two panes of polarized and partitioned glasses.
LCD [Cont.] • By adjusting the amount of light that passes through these panels through an electric voltage, images are created on the screen. • This technology also reduces blurring and colour smudging during motion pictures, which makes this type of monitor appropriate for gamers or film enthusiasts. • The Passive matrix LCD – One transistor for each row and each column of pixels, thus creating a grid that defines the location of each pixel
• The active matrix LCD – – – –
One transistor for one pixel Each pixel is turned on and off individually. Allows pixel refreshment more rapidly. Uses TFT (Thin Film Transistor) technology (4 transistors per pixel).
Electroluminescent Display ( ELDs) • Are similar to LCDs. • Use a phosphorescent film held b/w two sheets of glass. • A grid of wires sends current through the film to create an image.
Plasma Display • Display is created by sandwiching a special gas called Plasma (such as neon, xenon) between two sheets of glass. • When the gas is electrified via a grid of small electrodes, it glows. • By controlling the amount of voltage applied at various points on the grid. • Each point acts as a pixel to display an image.
General Monitor Features •
Size – – – –
•
the bigger the monitor the easier it will be on the eye. You will be able to open more windows and the text should be easier to read CRT have a smaller viewable area than their size. Monitor size (and TVs) are measured diagonally, from the top left corner to the bottom right hand corner
Resolution – Resolution is the number of pixels displayed on screen at one time – It's usually in the format Horizontal x Vertical, e.g.?- 800x600 or 1024x768. – The higher the resolution the more you can get on screen and the sharper the image.
•
Refresh Rate – This is the number of time the screen is redrawn per second – Most new monitors should have reasonable refresh rates, 75Hz or higher. – Some older CRTs had lower refresh rates that can cause screen flicker and induce eye strain.
•
Dot Pitch – Dot pitch is the distance in millimeters between two dots of the same colour on the screen, it's usually measured diagonally and you should be looking for something around 0.26mm
Video Cards • The quality of the image is defined by the video card as well. • It is also called a video controller / adapter. • It is an intermediary device b/w CPU and monitor. • It contains the video dedicated memory and other circuitry necessary to send info to monitor. • Modern video cards require a separate processor and video RAM. • Each pixel require one byte of information, so the number of bytes depend upon number of pixels (resolution).
Ergonomics and monitors • Eyestrain – Most frequent reported health problem. – Caused by continuously focusing on the same point. – How to avoid • Choose a monitor that holds a steady image without flickering (Dot pitch = .28 mm, Refresh rate = 72 Hz). • Position your monitor so it is 2.5 feet away from your eye. • Tilt the screen face 10 degree upward. • Place monitor where no light reflection occurs. • Keep your screen clean • Avoid looking at monitor for more than 30 minutes without break. • Do not let your eye dry.
Digital Light Processing (DLP) • •
• •
• •
Digital Light Processing (DLP) is a technology used in data projectors and video projectors. In DLP projectors, the image is created by microscopically small mirrors laid out in a matrix on a semiconductor chip, known as a Digital Micromirror Device (DMD). Each mirror represents one pixel in the projected image. The number of mirrors corresponds to the resolution of the projected image: 800x600, 1024x768, 1280x720, and 1920x1080 (HDTV) matrices are some common DMD sizes. These mirrors can be repositioned rapidly to reflect light either through the lens or on to a heat sink . Some old projectors use LCD technology to display
Sound card • Sound card is a circuit board that converts sound from Analog to digital and vice versa for recording and playback. • it facilitates the input and output sound under control of computer programs. • Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation/ education, and entertainment (games). • Many computers have sound capabilities built in, while others require these expansion cards if audio capability is desired.
TFT-LCD Monitor • A Thin Film Transistor (TFT) – LCD monitor is now being more widely used with LCD monitors, because of its high level of resolution and sharpness. • The only difference is a thin film transistor that is applied to the screen, which results in better control of pixels. • This type of monitor is recommended for those who play animated, colourful, and high-resolution games, as well as graphic artists who may need to check out different fonts on the computer screen.
Organic Light-Emitting Diode (OLED) •
•
• •
An organic light-emitting diode (OLED) is a thinfilm light-emitting diode(LED) in which the emissive layer is an organic compound OLED technology is intended primarily as picture elements in practical display devices. When the emissive electroluminescent layer is polymeric, varying amounts of OLEDs can be deposited in rows and columns on a screen using simple "printing" methods to create a graphical color display, for use as computer displays, portable system screens, and in advertising and information board applications. OLED may also be used in lighting devices. OLEDs are available as distributed sources while the inorganic LEDs are point sources of light.
Surface-conduction electronemitter display (SED) • • • • • • • •
Surface-conduction electron-emitter display (SED) is a flat-panel, high-resolution display. Some SEDs have a diagonal measurement exceeding one meter (approximately 40 inches). The SED consists of an array of electron emitters and a layer of phosphor, separated by a small space from which all the air has been evacuated. Each electron emitter represents one pixel. The SED requires no electron-beam focusing, and operates at a much lower voltage than a CRT. The brightness and contrast compare favorably with high-end CRTs. Prototype electron emitters have been developed with diameters of a few nanometers. SED technology can offer extraordinary image resolution
Speakers • Computer speakers, or multimedia speakers, are external speakers, commonly equipped with a low-power internal amplifier. • Headphones – It includes a pair of speakers attached to an adjustable strap. – These are lightweight and comfortable to use.
• Headset – It includes one or two speakers and a microphone all mounted to an adjustable strap.
Monitors • The monitor is the most commonly used output device of most PCs. • Image quality is determined by two devices – Monitor – Video Controller.
Categories of monitors • Monochrome monitors – Can display only one color (Red or Green or Blue) against a contrasting background – Used for text only display
• Grayscale monitors – Display varying intensities of grey
• Color monitors – Can display between 16 colors to 16 million colors.
CRT (Cathode Ray Tube) Monitor • • • •
• • •
CRT technology, computer monitors continue to be referred to as "The Tube". A CRT works by moving an electron beam back and forth across the back of the screen. Electron beam is fired by an electron gun. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby enlightening the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screen full of images. The smallest number of phosphor dots that the gun can focus on is called pixel (also called picture element. In colour monitors there are three colour beams Red, Green, Blue
Liquid Crystal Display (LCD) • A Liquid crystal display (LCD) is a thin, flat display device made up of any number of color or monochrome pixels arrayed in front of a light source or reflector. • It uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices. • LCD technology makes use of a liquid crystal solution that are present in two panes of polarized and partitioned glasses.
LCD [Cont.] • By adjusting the amount of light that passes through these panels through an electric voltage, images are created on the screen. • This technology also reduces blurring and colour smudging during motion pictures, which makes this type of monitor appropriate for gamers or film enthusiasts. • The Passive matrix LCD – One transistor for each row and each column of pixels, thus creating a grid that defines the location of each pixel
• The active matrix LCD – – – –
One transistor for one pixel Each pixel is turned on and off individually. Allows pixel refreshment more rapidly. Uses TFT (Thin Film Transistor) technology (4 transistors per pixel).
Electroluminescent Display ( ELDs) • Are similar to LCDs. • Use a phosphorescent film held b/w two sheets of glass. • A grid of wires sends current through the film to create an image.
Plasma Display • Display is created by sandwiching a special gas called Plasma (such as neon, xenon) between two sheets of glass. • When the gas is electrified via a grid of small electrodes, it glows. • By controlling the amount of voltage applied at various points on the grid. • Each point acts as a pixel to display an image.
General Monitor Features •
Size – – – –
•
the bigger the monitor the easier it will be on the eye. You will be able to open more windows and the text should be easier to read CRT have a smaller viewable area than their size. Monitor size (and TVs) are measured diagonally, from the top left corner to the bottom right hand corner
Resolution – Resolution is the number of pixels displayed on screen at one time – It's usually in the format Horizontal x Vertical, e.g.?- 800x600 or 1024x768. – The higher the resolution the more you can get on screen and the sharper the image.
•
Refresh Rate – This is the number of time the screen is redrawn per second – Most new monitors should have reasonable refresh rates, 75Hz or higher. – Some older CRTs had lower refresh rates that can cause screen flicker and induce eye strain.
•
Dot Pitch – Dot pitch is the distance in millimeters between two dots of the same colour on the screen, it's usually measured diagonally and you should be looking for something around 0.26mm
Video Cards • The quality of the image is defined by the video card as well. • It is also called a video controller / adapter. • It is an intermediary device b/w CPU and monitor. • It contains the video dedicated memory and other circuitry necessary to send info to monitor. • Modern video cards require a separate processor and video RAM. • Each pixel require one byte of information, so the number of bytes depend upon number of pixels (resolution).
Ergonomics and monitors • Eyestrain – Most frequent reported health problem. – Caused by continuously focusing on the same point. – How to avoid • Choose a monitor that holds a steady image without flickering (Dot pitch = .28 mm, Refresh rate = 72 Hz). • Position your monitor so it is 2.5 feet away from your eye. • Tilt the screen face 10 degree upward. • Place monitor where no light reflection occurs. • Keep your screen clean • Avoid looking at monitor for more than 30 minutes without break. • Do not let your eye dry.
Digital Light Processing (DLP) • •
• •
• •
Digital Light Processing (DLP) is a technology used in data projectors and video projectors. In DLP projectors, the image is created by microscopically small mirrors laid out in a matrix on a semiconductor chip, known as a Digital Micromirror Device (DMD). Each mirror represents one pixel in the projected image. The number of mirrors corresponds to the resolution of the projected image: 800x600, 1024x768, 1280x720, and 1920x1080 (HDTV) matrices are some common DMD sizes. These mirrors can be repositioned rapidly to reflect light either through the lens or on to a heat sink . Some old projectors use LCD technology to display
Sound card • Sound card is a circuit board that converts sound from Analog to digital and vice versa for recording and playback. • it facilitates the input and output sound under control of computer programs. • Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation/ education, and entertainment (games). • Many computers have sound capabilities built in, while others require these expansion cards if audio capability is desired.
TFT-LCD Monitor • A Thin Film Transistor (TFT) – LCD monitor is now being more widely used with LCD monitors, because of its high level of resolution and sharpness. • The only difference is a thin film transistor that is applied to the screen, which results in better control of pixels. • This type of monitor is recommended for those who play animated, colourful, and high-resolution games, as well as graphic artists who may need to check out different fonts on the computer screen.
Organic Light-Emitting Diode (OLED) •
•
• •
An organic light-emitting diode (OLED) is a thinfilm light-emitting diode(LED) in which the emissive layer is an organic compound OLED technology is intended primarily as picture elements in practical display devices. When the emissive electroluminescent layer is polymeric, varying amounts of OLEDs can be deposited in rows and columns on a screen using simple "printing" methods to create a graphical color display, for use as computer displays, portable system screens, and in advertising and information board applications. OLED may also be used in lighting devices. OLEDs are available as distributed sources while the inorganic LEDs are point sources of light.
Surface-conduction electronemitter display (SED) • • • • • • • •
Surface-conduction electron-emitter display (SED) is a flat-panel, high-resolution display. Some SEDs have a diagonal measurement exceeding one meter (approximately 40 inches). The SED consists of an array of electron emitters and a layer of phosphor, separated by a small space from which all the air has been evacuated. Each electron emitter represents one pixel. The SED requires no electron-beam focusing, and operates at a much lower voltage than a CRT. The brightness and contrast compare favorably with high-end CRTs. Prototype electron emitters have been developed with diameters of a few nanometers. SED technology can offer extraordinary image resolution
Speakers • Computer speakers, or multimedia speakers, are external speakers, commonly equipped with a low-power internal amplifier. • Headphones – It includes a pair of speakers attached to an adjustable strap. – These are lightweight and comfortable to use.
• Headset – It includes one or two speakers and a microphone all mounted to an adjustable strap.
