Different Types of Electronic Displays - Essay Example

Electronic Displays Electronic displays are commonly used in personal computers, car navigation systems, mobile phones, televisions and other electronic devices (Namikawa 2007, p119). There are different types of electronic displays, usually classified according to technology, application, and environment. Different Types of Electronic Displays Different Types of Electronic Displays According To Technology The major electronic displays technologies include the following; Cathode Ray Tube (CRT), Electro-Luminescent Display (ELD), Flip-Dot Display, Incandescent Display (Light Bulb), Liquid Crystal Display (LCD), Light Emitting Diode (LED), Organic LEDs (OLED) Polymer LEDs (PLED), Glow Discharge (Plasma) Indicators (Nixie), Plasma Display Panel (PDP), and Vacuum Fluorescent Display (VFD) (Maxim Integrated Products 2002, p1). Electronic paper is a more recent electronic display technology (Facchetti and Marks 2010, p213). Cathode Ray Tube (CRT) CRT is a vacuum tube that uses a hot filament to produce electrostatic, magnetic fields, and thermo-electrons to “focus the electrons into a beam attracted to the high voltage anode which is the phosphor emit luminous radiation” (Maxim Integrated Products 2002, p1). Color CRTs generally utilize three electron sources or guns to target blue, green, and red phosphor prototypes to the screen. Electro-Luminescent Display (ELD) EL display is a solid-state display that uses phosphor to discharge light or a beam in the presence of an electric field. Phosphors utilized are generally green or yellow-orange (Maxim Integrated Products 2002, p1). Flip-Dot Display Each pixel is composed of a hinged disk. The disk is characterized by a reflective or a fluorescent (lit) on one side and a matt black on the other side (unlit). Various methods are used to flip the disk. One technique balances the disk around the electromagnetic soft iron framework. The winding is strengthened to attract the disk towards either of the sides. The remanent magnetism grasps the position and thus, only a small amount of energy (power pulse) is needed to flip the pixel. Incandescent Display (Light Bulb) A tungsten filament (which is coated) is run white hot in the vacuum. The filament generates both infrared (heat) and visible light. Liquid Crystal Display (LCD) LCD utilizes the liquid crystals properties in an electric field to direct light from the opposite polarized back and front display plates. The liquid crystal functions as a helical director to direct the light or beam through 90 degrees from one plate to the other plate. It is important to note that the liquid crystal acts as a director only when the driver gives the correct electric field (Maxim Integrated Products 2002, p2). Light Emitting Diode (LED) LED is a photon generating semiconductor, which generates light due to the effect of injection electroluminescence. The emitted light wavelength varies primarily because of the semiconductor material chosen and it is generally in infrared or a visible spectrum. Organic LEDs (OLED) Polymer LEDs (PLED) These forms of display utilize organic electroluminescent materials placed on flexible or a glass substrate. OLEDs are devices dependent on small organic polymer molecules and PLEDs are devices based on the large organic polymer molecules. Light is emitted through injection electroluminescence just like LEDs. The “choice of organic material sets the emission color OLED pixels are capacitive (tens to hundreds of pictofarads) leading to significant switching losses for large displays with high multiplex ratios” (Maxim Integrated Products 2002, p3). Glow Discharge (Plasma) Indicators (Nixie) Inert gas within a tube (the tube is composed of two electrodes under high voltage) is ionized permitting current to emerge around the cathode. When the tube is driven from an alternating current (AC) source such as a neon indicator, the glow discharge emerges from both electrodes. Sophisticated displays utilize either multiple cathodes designed as complete numerals (each lit at a time) or segments (a character is made from one or more lit). Plasma Display Panel (PDP) Plasma displays utilize several controlled gas discharge paths (each path features color and a pixel), however, the inert gas is set to glow external to the visible spectrum. Each local current discharge path ends with its individual phosphor coated cathode. The cathode in turn generates luminous radiation. They can be set as RGB triads to create a color display (Maxim Integrated Products 2002, p4). Vacuum Fluorescent Display (VFD) VFD is a vacuum tube that uses hot filaments to produce thermo-electrons, “A grid (static display type) or multiple grids (multiplexed display type) control and diffuse the thermo-electrons, which are attracted to one or more high voltage phosphor coated anodes, which then emit light” (Maxim Integrated Products 2002, p5). The anodes are situated at the back of the display and thus, the generated light passes via the grid, the filaments, and the display front, from which the user is able to see. It is important to note that the filaments are not made hot enough in order to be visible (Maxim Integrated Products 2002, p5). Electronic Displays According To Application and Environment The application of electronic displays ranges from surgical glasses to mobile phones and each device necessitates access to various forms of electronic data entailing major technological challenges (Carayannis and Chanaron 2007, p108). CRTs have dominated the display industry for many years. However, recent trends such as the need for mobile electronics have elevated the demand for displays are better than CRTs in terms of size, power consumption, and picture quality. LCD is one the latest technology that is likely to replace CRTs because its lightness, compact design, and low power consumption. LCD has permitted the development of devices such as cell phones, laptops, digital watches, and other small-screened electronics. The initial purpose for developing LCDs was portable and handled devices; however, their use has expanded to televisions and computer monitors (Gurski and Quach 2005, p3). CRT displays possess excellent quality and color reliability and they are relatively cheap to produce. Thus, they are widely used in homes, printing and broadcasting industries. They have exemplary response time and thus, they are suitable for fast-moving images like video games. Because of their non-native resolution abilities, they are flexible and compatible with most video outputs. They are capable of running at various refresh and resolution settings (Skilton 2006, p4). LCDs are thin and they have less weight, thus, their flexibility in their practical use. Because of their nature, LCDs can be integrated into sleek compact cases (Skilton 2006, p5). Plasma screen technology facilitates high contrast ratios than most of the direct view televisions. They have rich color production and a wide viewing angle and thus, they are capable of generating exemplary image quality (Skilton 2006, p6). Electronic Displays Used In Handheld Devices Majority of the handheld devices displays use (OLED) organic light emitting diodes. OLEDs are used in handheld devices such as cell phones and GPSs. An OLED display device uses less power than LCD screens. OLEDs possess a bright and a crisp image and its response rate is faster than the standard LCD screen (Oja and Parsons 2010, p28). OLED technology is regarded as exceptionally suitable for the development of flexible and ultrathin FPDs (flat panel displays) from carbon-based compounds. The technology also makes it possible to have full color displays that possess viewing quality better than those of other technologies do. The positive characteristics that allow OLED displays to generate more information in an efficient manner include: Inherent self-luminosity, a feature that lacks in LCDs. This feature helps avoid the need for polarizing filters and bulky backlights when using black layer. In other words, OLEDs are emissive displays (they produce their own light) and thus, they do not require backlighting. The self-luminous effect also enables OLEDs displays to have a large viewing angle (Gurski and Quach 2005, p23). A thinner, more compact, and a space-saving screen that has the best possible viewing angle. Low power consumption provides significant advantage for portable applications and it assists in reducing heat and electronic interference. A faster response time – the response time is a hundred times faster than that of the LCDs (Statham 2005, p6). OLED displays possess extremely high switching speeds and thus, they can handle high refresh rates needed for full-motion videos (Gurski and Quach 2005, p23). It is worth noting that the present displays used in handheld devices such as plasma display panels (PDPs), organic light emitting diodes (OLEDs), and liquid crystal displays (LCDs) are not suitable for immersive or intensive reading in comparison to electronic paper. In the past few years, electronic paper has emerged as the next generation media. Electronic paper has advantages of both electronic and paper display (Facchetti and Marks 2010, p213). It is electronically rewritable and “consumes ultra low power with high brightness and contrast with full viewing angle like real paper” (Facchetti and Marks 2010, p214). Electronic paper is applied in electronic newspapers, watches, electronic billboards, cellular phones, electronic book readers, electronic pricing labels used in retail shops, destination boards of the subway trains, and time tables at the bus stations (Facchetti and Marks 2010, p214). As stated earlier, electronic has excellent reflective, image stable and rewritable characteristics. The most important feature of electronic paper is the rewritable aspect. Reflective and image stable characteristics are important for the realization of ultra low power consumption. Outside light is important in reflective display because it assists in the viewing of the displayed image. However, reflective display does not consume much power like emissive display; emissive display requires a considerable amount of energy to produce its own light. On the other hand, image stability provides further power saving; energy is only consumed when there is a change of the image. It is important to note that the energy consumed serves the purpose of changing the image and not maintaining it. Other benefits of electronic paper are that it is light, thin, displays color image with high flexibility and resolution, and it has a high contrast (Facchetti and Marks 2010, p214). Constraints In Relation To the Design of the Display OLED also referred to as light emitting polymer (LEP) or organic electroluminescence (OEL) is a light generating diode. Its electroluminescent layer has polymers that permit the deposition of suitable organic compounds. The polymers are deposited in columns and rows on the flat carrier through the printing process. The matrix of pixels can generate light with varying colors when an electric field is applied on it. As stated before, OLEDs are more beneficial than LCD displays which need back illumination. However, the use of OLED has been limited due to the degradation of its materials. There is ongoing research to reduce the degradation of OLED materials (Kao 2010, p178). Sustainability involves maintenance and consumption of the world resources. OLED displays have several advantages over the traditional LCD screens concerning the issues of sustainability. OLEDs consume less energy than LCD screens and thus, they are more energy efficient; this is because they do not require backlight. Energy efficiency reduces carbon dioxide emissions and money used in the generation of energy. OLEDs do not have toxic materials like those that LCD displays have; this means that they do not pollute the environment heavily. Traditional electronics have many hazardous chemical that necessitates unique disposal techniques. OLED displays do not require these unique disposal techniques thus, saving resources and time. However, OLED have several sustainability disadvantages in comparison to the traditional electronics. Current OLED displays have a short lifespan compared to other electronic displays serving the same functions. Thus, the cost of creating and replacing OLED displays may overshadow the advantages of energy efficiency (Delacruz 2010, p1). Most of the flat screen displays such as LCDs possess fluorescent tube backlights; however, smaller devices (like calculators) do not have these backlights. Mercury is contained in these fluorescent tube backlights and they are recognized as hazardous elements in the Electronic Waste Catalogue (EWC). If a waste monitor has fluorescent tube backlight, it is considered a hazardous waste. However, there is little information concerning LCD substances. OLED and plasma monitor function in a different manner and they do not need backlight, however, there is limited information (if they are hazardous or not) concerning them (Environment Agency 2010, p2). References Carayannis, E. G. (2007) Leading and managing creators, inventors, and innovators: The art, science, and craft of fostering creativity, triggering invention, and catalyzing innovation, Westport, CT: Greenwood Publishing Group. Delacruz, G. (2010) Sustainability [online]. Available from: [accessed 12 Jan. 2012]. Environment Agency. (2010) Classification of electronic display devices [online]. Available from: [accessed 12 Jan. 2012]. Facchetti, A. & Marks, T. J. (2010) Transparent electronics: From synthesis to applications, Hoboken, NJ: John Wiley and Sons. Gurski, J. & Quach, L. M. (2005) Display technology overview [online]. Available from: [accessed 12 Jan. 2012]. Kao, R. W. Y. (2010) Sustainable economy: Corporate, social and environmental responsibility, Hackensack, NJ: World Scientific Publishing. Maxim Integrated Products. (2002) Electronic displays comparison (online), Maxim. Available from: [accessed 12 Jan. 2012]. Namikawa, R. (2007) International deployment of the Japanese electronic materials industry: Cases of electronic display materials manufacturers. The International Journal of Economic Policy Studies, 2(8), pp.117-137. Oja, D. & Parsons, J. (2010) Computer concepts – Illustrated introductory, Mason OH: Cengage Learning. Skilton, D. (2006) Electronic display system: A comparative study [online]. Available from: [accessed 12 Jan. 2012]. Statham, S. (2005) New display technologies [online]. Available from: [accessed 12 Jan. 2012]. Read More