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Smartphone Crowd Computing: A Rational Approach for Sustainable Computing by Curbing the Environmental Externalities of the Growing Computing Demands
Published in Rik Das, Mahua Banerjee, Sourav De, Emerging Trends in Disruptive Technology Management for Sustainable Development, 2019
Pijush Kanti Dutta Pramanik, Saurabh Pal, Prasenjit Choudhury
In a computer system, in comparison to the other components and peripherals, the display device (monitor) consumes the most energy. Even when the computer is idle, the display device continually keeps consuming energy. For sustainable computing, display devices should be energy-efficient. There are two ways seen for reducing energy consumption by display devices. One is integrating low-power consumption technology for display, and the other is efficient power management, which makes sure the display device hibernates when it is in an idle state. Earlier, the use of CRT technology consumed a lot of energy, but their replacements by LCD and subsequently, light-emitting diode (LED) technologies have reduced the power consumption considerably. Further, in comparison to LCD monitors, which typically use a cold-cathode fluorescent bulb to provide light for the display, the LED monitors use an array of LEDs. Thus, LED reduces the amount of electricity used for display; moreover, LEDs are mercury-free and nontoxic as compared to LCDs.
Video Basics
Published in Wes Simpson, Video Over IP, 2013
Liquid crystal displays (LCDs) use liquid crystals (chemicals that can be used to block or pass light based on an electrical signal) and a light source to create a viewable image, either directly on a glass sheet or by projecting the light onto a screen. Plasma displays use electron beams and phosphors just like a CRT, except each pixel has its own microscopic beam source. Large outdoor displays can use thousands upon thousands of light-emitting diodes (LEDs, just like the ones used as power indicators on electronic devices) in three different colors to create an image. And finally, Digital Light Processing® (DLP) projectors use devices from Texas Instruments containing millions of movable microscopic mirrors to reflect light from three different color light sources onto a display screen.
Real-Time Alarm Clock Using Arduino
Published in Anudeep Juluru, Shriram K. Vasudevan, T. S. Murugesh, fied!, 2023
Anudeep Juluru, Shriram K. Vasudevan, T. S. Murugesh
OLEDs are generally more power-efficient compared to LCDs. OLEDs consume power depending on the content displayed on the screen whereas LCDs consume almost the same power irrespective of the content displayed on the screen. When displaying content with more black colour, OLEDs consume the least power as they need to just switch OFF the pixels at the places where the content is black. But, when displaying content with more white colour, OLEDs require more power as they need to switch ON most of the pixels whereas LCDs consume constant power irrespective of the content as it uses the same backlight for any type of content. Each pixel in an OLED has an organic component whereas pixels in LCD don’t. So, the life of OLEDs tends to be low compared to LCDs.
The Changing Face of Public Broadcasting in India
Published in IETE Journal of Education, 2023
The CRT display has become obsolete now and has been overtaken by LCD displays. The ones put in the market, by the name of LED displays, are also LCD displays, except that the white light source in the back plane is an array of LED’s. The old LCD used a gas discharge tube for backplane illumination. The LCD display is x, y addressed type and individual pixels are defined by address lines. Color signals are steered to individual corresponding LCD elements. Thus the previous discussions, pertaining to signals created with CRT display in mind, have just lost relevance, in the context of LCD display. Address lines and color signal become important for the case of LCD / LED displays. The video interface of yesterday is deeply entrenched in the industry and a decoder is used in the LCD displays to handle analog composite video signals (CVSB). Display standards for TV have been given in Table 2.
Rising advancements in the application of PEDOT:PSS as a prosperous transparent and flexible electrode material for solution-processed organic electronics
Published in Journal of Information Display, 2020
Gunel Huseynova, Yong Hyun Kim, Jae-Hyun Lee, Jonghee Lee
OLEDs are flat self-light-emitting optoelectronic devices commonly applied for display and solid-state lighting technologies [11,33,65]. The simple structure of OLEDs consists of multilayers formed from organic materials functioning as an HTL, a light-emitting active layer, and an electron transport layer (ETL) stacked between two transparent and reflective electrodes called ‘anode’ and ‘cathode,’ respectively [33]. The main parameters defining the efficiency of OLED devices include the external quantum efficiency (EQE), turn-on voltage (VT), current density, current efficiency, power efficiency, color quality, and lifetime [33,66]. OLEDs are ultra-thin, ultra-light, flexible, and simple in design, as well as suitable for large-area electronics [11]. OLED displays are more efficient than liquid crystal displays (LCDs), and they deliver better image quality for lower power consumption. In addition, they do not require a backlight, as LCDs do [85]. OLEDs can also be a safe and excellent light source. They are both transparent and color-tuneable [86]. Although the first practical OLED appeared a little more than 30 years ago, the flexible OLEDs have been on the market for many years, and are the important components for the realization of the future flexible, wearable, foldable, and even biodegradable optoelectronic applications [85–87].
Accurate measurement of the twist elastic constant of liquid crystal by using capacitance method
Published in Liquid Crystals, 2019
Wenjiang Ye, Zhenjie Li, Rui Yuan, Ping Zhang, Tingting Sun, Minglei Cai, Xiaoyan Wang, Jiliang Zhu, Yubao Sun, Hongyu Xing
The basic principle of liquid crystal display (LCD) is that liquid crystal (LC) molecules, which are oriented by external voltage, adjust light through the LCD [1]. The orientation of LC molecules, including three kinds of basic deformations, namely, splay, twist and bend, can be determined by the splay, twist and bend elastic constants k11, k22 and k33, respectively. The elastic constants of LC are important material parameters, which directly affect the performance of LCD, such as response time and threshold voltage [2]. Thus, the accurate measurement of the elastic constants of LC, especially the twist elastic constant (k22), is vital in knowing the material properties of LC and optimising LCDs [3–7].