dual led vs direct led
The light emitting diode is the most visible type of semiconductor diode. They emit a fairly narrow bandwidth of either visible light at different coloured wavelengths, invisible infra-red light for remote controls or laser type light when a forward current is passed through them. The “ Light Emitting Diode ” or LED as it is more commonly
The LED for reflected illumination uses one objective lens to perform the role of both an objective and condenser, so the necessary light flux diameter is smaller. With this design, the numerical aperture (NA) is perfectly matched. This results in the optimal focusing of light and collection of light at the sample plane. Obviously, LED lamps have two ends and four pins (two pins on each end) to hold it in place regardless of installation, type, or length. When an LED lamp is “single-end powered”, this means the LED lamp is powered from one end only. But, when electricity is wired to power the LED lamp from both ends, this is a “double-end powered” lamp Dual-cell LCDs use a simple, unzoned backlight, with the zones provided by a monochrome LCD that sits behind the color LCD the viewer sees. For a color LCD with CR of 2000:1 and a twisted nematic monochrome LCD with CR of 1000:1, the measured CR of the system is greater than one million to one; the system delivers a 16-bit color depth with a 5QLED. Displays from 32 inches to 85 (and up). More expensive. Since some ULED TVs have QLED screens, it's hard to make a direct price comparison between the two. A ULED without a quantum-dot display will cost less because that technology is more expensive than a standard LED screen.
Direct lit LED. Direct lit LED backlighting uses LED lighting across the back of the TV, directly behind the LCD panel, providing a fairly uniform amount of light across the screen. It