Most discussions on industrial LCD technology categorization revolve around the subject of operating technologies that work at the backend to produce pictures in an LCD display. These technologies include Twisted Nematics (TN), In-Plane Switching (IPS), Vertical Alignment (VA), Multidomain Vertical Alignment (MVA), Advanced Fringe Field Switching (AFFA) and Blue Phase Mode (BPM).
However, there exist another major categorization criteria that categorize LCD technology based on the type of light source used to illuminate the liquid crystals found in an LCD display.
LCD technology types based on illumination sources
Based on the type of light source used for illumination, LCD technology can be divided into three distinct categories:
Transmissive LCD technology
Transmissive LCD technology uses a backlight to illuminate liquid crystal layers.
There are two types of backlights used as light sources in transmissive LCDs: CCFL backlights and LED backlights.
Most modern transmissive LCDs employ LEDs as backlights. This is because in comparison to CCFL lights, LED backlights produce images with a higher dynamic contrast, offer wider color gamut, produce less heat and are more energy efficient.
Three different types of LEDs are used as backlights in transmissive LCD displays, including edge-lit LEDs, full array LEDs and dynamic dimming LEDs.
Transmissive LCD technology is exclusively used in LCD panels that are designed for indoor applications as it offers poor readability in sunlight or bright ambient light.
Reflective LCD technology
Reflective LCD technology uses ambient light (sunlight, room light, office light etc.) as light source for illuminating the display. It’scommonly used in the design of LCD panels developed for outdoor settings.
In terms of design, reflective LCD technology employs a high performing reflector that is installed at the back of the screen andreflects the ambient light to illuminate the liquid crystal layers.
Compared to transmissive LCDs, reflective LCDs have lower power requirements, are lighter and slimmer in design andoffer better outdoor readability. However, unlike their counterparts, they are inapplicable and highly ineffective under low or dark ambient conditions.
Transflective LCD technology
Transflective LCD technology combines the advantages of both transmissive and reflective LCD technologies; it displays images in transmissive (T) mode as well as in reflective (R) mode.
How does the technology accomplish a dual-mode display?
Transflective LCDs are designed with backlights and transflectors which enable them to operate in both T and R modes. When the conditions are bright, the illumination sensors present in the displays switch off the backlights and use ambient light as the light source. Under dark conditions, the backlights are turned on for illumination. In low-to-medium light, they run in both T – and R-modes simultaneously.
A variety of transflector types are used in the design of transflective LCDs. This includes:
- Openings-on-metal transflector
- Half-mirror metal transflector
- Multilayer dielectric film transflector
- Orthogonal polarization transflector
Transflective LCDs can be commonly found in cell phones, digital assistants, pocket PCs, premium digital signage, global position and navigation systems etc.
Do you have any questions about transmissive, reflective or transflective industrial LCD technologies? Feel free to ask; REVO will be happy to answer them.
REVO is a leading global marketplace for high-performing industrial LCD display solutions. The company works with OEMs, contract manufacturers and independent electronic distributors to provide them high quality industrial LCD displays for their different design needs. For more details, please call 1-866-738-6797 or visit the company’s official website.