Monitors and displays are screens for viewing video information and can be used for a wide variety of applications such as in desktop and lap top computers, digital cameras, camcorders, entertainment and mobile computer accessories. Monitors and displays use different technologies with respective advantages and drawbacks. Those technologies include cathode-ray tube (CRT), liquid crystal display device (LCD), the plasma display panel (PDP), the electroluminescent display (ELD), and the vacuum fluorescent display (VFD). Liquid crystal displays (LCDs) are used in a wide variety of commercial applications, including computers, PDAs (personal digital assistant), palm-top computers, cellular phones, camcorders, and television screens. The liquid crystal display (LCD) or thin-film transistor liquid crystal display (TFT-LCD) has gradually replaced the cathode ray tube (CRT) to become a mainstream product due to its excellent properties of low radiation and low power consumption. Cathode ray tube (CRT) displays create images by impinging an electron beam on the face of an evacuated glass tube that has been coated with phosphors that emit light at the primary colors. Cathode-ray tube (CRT) displays had been the predominant display technology for purposes such as home television screens and computer monitors. Flat panel display devices are widely used in personal computers, TV, and game machines, because of their characteristics of thinness, lightness, and low power consumption. A flat panel display device can be a liquid crystal display device, a plasma display device, or an electroluminescence device. Electroluminescent displays work by making use of electroluminescence phenomenon in which light is generated when an electric field of certain intensity is applied to a fluorescent substance. The organic electroluminescent display (ELD) device has drawn attention as a displaying device for natural colors because it can display every color in a range of a visible light and has a high brightness and a low operating voltage. A touch screen is a device placed over or above a display which provides a signal when the screen is mechanically touched. Touch screens are becoming more prevalent as data input interfaces as computers and other electronic devices become more ubiquitous.
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Saturday, 04 November 2006 |
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A plasma display panel (PDP) is a display device in which ultraviolet rays generated by the discharge of gas excites phosphors to realize predetermined images. In a plasma display panel, ultraviolet rays are generated by discharging gas and exciting phosphor to emit light for a color display. PDPs may be classified as direct current (DC) type and alternating current (AC) type according to voltage driving waveforms and discharge cell structures. A plasma display panel has better characteristics than a liquid crystal display because it has a faster responding speed, a wider viewing angle, easier to produce a larger screen, and higher display quality due to self-light-emitting. It attracts attention as the primary substitute for conventional cathode ray tubes (CRTs) for large-screen displays. |
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Monday, 23 October 2006 |
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A vacuum fluorescent display (VFD) is an electron tube which displays a desired pattern by causing electrons emitted from the cathode in the vacuum vessel (envelope) which is transparent to impinge on the phosphor applied to the anode and causing the phosphor to emit light. Vacuum fluorescent displays require a filament power supply to heat the filament to a temperature suitable for proper emission of electrons which are accelerated by an anode potential onto a fluorescent material to emit light. Typical vacuum fluorescent displays include a filament, a suspended acceleration grid, anodes and phosphors, all enclosed within a sealed package having a low pressure. A vacuum fluorescent display is capable of producing multi-colored images with a low voltage, and is well adapted to the semiconductor appliances. |
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Sunday, 15 October 2006 |
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Flat panel monitors employ technologies such as thin film transistor (TFT) LCD, organic light emitting diode (OLED), plasma display panel (PDP), and field emission display (FED) to display image. The flat panel display receives image signals and horizontal and vertical synchronizing signals. The received image signals are synchronized by the flat panel display according to the horizontal and vertical synchronizing signals and displayed. An LCD monitor displays images by a refractive index difference utilizing optical anisotropy properties of a liquid crystal material. The principle of operation of a plasma flat panel display is the conversion of ultraviolet radiation into visible light by phosphors. Vacuum fluorescent displays utilize thermal emission of electrons from a cathode and phosphor excitation. |
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Thursday, 05 October 2006 |
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Field emission display (FED) devices are an alternative to cathode ray tube (CRT) and liquid crystal display (LCD) devices. A field emission display includes a cathode plate containing an electron emitting surface (emission tip) that when driven, emits electrons toward a thin glass faceplate or anode plate coated with patterned phosphor. A FED has a structure in which a cathode where an electron emission source is formed so as to emit electrons on a substrate, and a gate electron for inducing field emission are formed in an array. Field emission devices may be used in making flat panel display devices for providing visual display for computers, telecommunication and other graphics applications. Flat panel displays have a greatly reduced thickness compared to the generally bulky cathode ray tubes. |
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Monday, 18 September 2006 |
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A light emitting diode (LED) is a semiconductor light emitting device, which emits various colors of light, with light sources being constituted by compound semiconductors made of various materials. Light-emitting diodes have long life expectancy, high tolerance to humidity, low power consumption and minimal heat generation. LED display panels use matrix addressing techniques to organize the light emitting elements or pixels into a number of rows and columns with each pixel at an intersection of a particular row and a particular column. LED display panels are widely used to create images for visual displays in a variety of applications including communication and visual display devices. Organic light emitting diodes (OLED) displays have high brightness, fast response speed, full color, and low cost. |
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Thursday, 07 September 2006 |
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A touch screen is a device placed over or above a display which provides a signal when the screen is mechanically touched. A touch screen allows the user of a terminal to enter a menu selection or data by placing a finger or other object at a location on the display screen that corresponds to the menu item, function or data numeral to be entered. Touch screens are more convenient than conventional computer screens because the user can directly point to an item of interest on the screen instead of having to use a mouse or other pointer. A touch screen employs one of four types of touch technologies: capacitive, resistive, infrared, and surface acoustic wave. A resistive touch screen works by applying a voltage across a resistor network and measuring the change in resistance at a given point. |
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Friday, 01 September 2006 |
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Liquid crystal display (LCD) has many advantages over other conventional types of displays including high display quality, small volume occupation, lightweight, low voltage driven and low power consumption. A liquid crystal display device uses the optical anisotropy and polarization properties of liquid crystal molecules to produce an image. Active matrix liquid crystal displays use thin film transistors (TFT) as switching devices to display pictures corresponding to video signals inputted to a pixel matrix. Generally, liquid crystal display devices can be classified as a transmissive liquid crystal display device, a reflective liquid crystal display device, or transflective LCD device. The transflective liquid crystal device is widely used as a display unit in portable devices and other various systems. |
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Saturday, 19 August 2006 |
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A liquid crystal display device has a number of advantageous features including light weight, reduced thickness and low power consumption. LCD monitors have been widely applied to several portable information products, such as notebooks, PDAs, digital cameras, cell phones. The LCD monitors gradually replace the CRT monitors of the conventional desktop computers. Liquid crystal displays utilize such variations in optical properties to display an image. The LCD device is largely classified into a TN (twisted nematic) type and a STN (super-twisted nematic) type displays. Currently, the mainstream LCD is a TFT (thin film transistor) LCD, which is an active matrix type. Because of high displaying quality and small size, LCD monitors have become increasingly popular in a wide variety of applications. |
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Monitors and Displays
