LCD (Liquid Crystal Display) is a type of flat panel display that uses liquid crystals in the primary mode. LEDs have a wide and varied range of use cases for consumers and businesses, as they are commonly found in smartphones, televisions, computer monitors, and instrument clusters.
LCD displays were a huge step forward in terms of the technology they replaced, including light-emitting diodes (LEDs) and gas plasma displays. LCD screens allowed screens to be much thinner than cathode ray tube (CRT) technology. LCD screens consume much less energy than LEDs and gas screens because they work on the principle of blocking light instead of emitting it. When an LED emits light, the liquid crystals in an LCD display produce an image using backlighting.
As LCD screens have replaced the old display technologies, LCD screens are starting to be replaced by new display technologies such as OLEDs.
How LCDs work
A screen is made up of millions of pixels. The quality of a screen generally refers to the number of pixels; for example, a 4K screen consists of 3840×2160 or 4096×2160 pixels. A pixel is made up of three subpixels; red, blue, and green – commonly called RGB. When the sub-pixels of a pixel change color schemes, a different color can be produced. When all the pixels on a screen work together, the screen can create millions of different colors. When the pixels are turned on and off quickly, an image is created.
The way a pixel is checked is different for each type of screen; CRT, LED, LCD, and newer screens have different pixel control. Basically, LCD screens are backlit and the pixels turn on and off electronically while liquid crystals are used to rotate polarized light. A polarizing glass filter is placed in front of and behind all pixels, the prefilter is positioned at 90 degrees. Between the two filters are liquid crystals, which can be switched on and off electronically.
LCD screens are made with a passive or active matrix display grid. The active matrix LCD display is also known as a thin-film transistor (TFT) display. The passive matrix LCD screen has a grid of conductors with pixels located at each intersection of the grid. A current is sent through two conductors on the grid to control the light of each pixel. An active matrix has a transistor located at each pixel intersection, which requires less current to control the luminance of a pixel. For this reason, on an active matrix display, the power can be turned on and off more frequently, improving the refresh time of the display.
Some passive-matrix LCDs are dual scan, which means they scan the grid twice with power in the same amount of time it takes to scan with the original technology. However, the active matrix is still a technology superior to both. There are many Wholesale Laptop LCD Screen manufacturers available in your location which can provide these LCDs at a cheaper price.
Types of LCDs
- Twisted Nematic (TN), are inexpensive and have high response times. However, TN displays have low contrast ratios, viewing angles, and color contrasts.
- In panel switching displays (IPS panels), have much better contrast ratios, viewing angles, and color contrast than TN LCD displays.
- Vertical Alignment Panels (VA Panels): Which are considered to be an average quality between TN and IPS displays.
- Advanced Fringe Field Switching (AFFS), is one of the best IPS displays compared to IPS displays in the color reproduction range.