automotive flat rate backlight replacement monitor repairs backlight replacement projector replacement bulb projector repair
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 is prized by engineers because it uses very small amounts of electric power, and is therefore suitable for use in battery-powered electronic devices. Enlarge Zero-power displays Vertical Alignment displays are a form of LC displays in which the liquid crystal material naturally exists in a horizontal state removing the need for extra transistors (as in IPS). When no voltage is applied the liquid crystal cell, it remains perpendicular to the substrate creating a black display. When voltage is applied, the liquid crystal cells shift to a horizontal position, parallel to the substrate, allowing light to pass through and create a white display. VA liquid crystal displays provide some of the same advantages as IPS panels, particularly an improved viewing angle and improved black level.
* Thin-film transistors and color filters
Menu:
We are laptop repair specialists!
We have qualified, A+ Certified Technicians ready to diagnose your laptop!
Whether you need a new part, or simply do not know why your laptop is acting up, feel free to give our technicians a call to give you an estimate. MORE
Our A+ Certified Technician will diagnose your laptop completely, and inform you of the problem. Estimated parts and labor to fix it will be given upon completion of testing... MORE
A computer display, monitor or screen is a computer peripheral device capable of showing characters and/or still or moving images generated by a computer and processed by a graphics card. Monitors generally conform to one or more display standards. Sometimes the name "display" suits better than the word "monitor", as the latter term can also ambiguously refer to a "machine-level debugger" or to a "thread synchronization mechanism". Some people also refer to computer displays as "heads", especially when talking about multiple displays connected to a single physical computer. Once an essential component of a computer terminal, computer displays have long since become standardized peripherals in their own right. Some LCD panels have defective transistors, causing permanently lit or unlit pixels. Unlike integrated circuits, LCD panels with a few defective pixels are usually still usable. It is also economically prohibitive to discard a panel with just a few bad pixels because LCD panels are much larger than ICs. Manufacturers have different standards for determining a maximum acceptable number of defective pixels. The following table presents the maximum acceptable number of defective pixels for IBM's ThinkPad laptop line. Brief history
Active matrix technologies LCD panels are more likely to have defects than most ICs due to their larger size. In this example, a 12" SVGA LCD has 8 defects and a 6" wafer has only 3 defects. However, 134 of the 137 dies on the wafer will be acceptable, whereas rejection of the LCD panel would be a 0% yield. The standard is much higher now due to fierce competition between manufacturers and improved quality control. An SVGA LCD panel with 4 defective pixels is usually considered defective and customers can request an exchange for a new one. The location of defective pixels is also important. A display with only a few defective pixels may be unacceptable if the defective pixels are near each other. Manufacturers may also relax their replacement criteria when defective pixels are in the center of the viewing area. IPS (In-Plane Switching) was developed by Hitachi in 1996 to improve on the poor viewing angles and color reproduction of TN panels. These improvements came at a loss of response time, which was initially on the order of 50ms. IPS panels were also extremely expensive. Competing displays include the Cathode ray tube, OLED, AMLCD, DLP, SED-tv and field emission flat panel displays. The main advantage of plasma display technology is that a very wide screen can be produced using extremely thin materials. Since each pixel is lit individually, the image is very bright and looks good from almost every angle. Because many plasma displays still have a lower resolution the image quality is often not quite up to the standards of good LCD displays or cathode ray tube sets, but it certainly meets most people's expectations. Also, most cheaper consumer displays appear to have an insufficient color depth - a moving dithering pattern may be easily noticible for a discerning viewer over flat areas or smooth gradients; expensive high-res panels are much better at managing the problem.