A row of LEDs mounted to the panel’s frame, or circumference, shine horizontally onto a light-guide plate (LGP) to form an edge-lit LED panel. Through a diffuser, the LGP transmits light downward, into the area below. Side-lit panels are another name for edge-lit panels.
An array of LEDs mounted on a horizontal plate that shine vertically down through a diffuser onto the area that needs to be lighted makes up a back-lit LED panel. Direct-lit panels are another name for back-lit panels.
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Which LED panels are better, backlit or edge-lit?
There are benefits and cons to both designs. The first panels to be mass-produced were edge-lit ones.
Initially, the edge-lit design was employed for many reasons:
A light-guide plate (LGP) is a quick and easy solution to disperse light evenly and reduce the possibility of glaring spots. Acrylic (PMMA), which has a very high light transmission percentage and doesn’t yellow with age, is used to make the greatest LGPs.
Low-cost materials can be used in the diffuser as long as they don’t yellow with age since the LGP ensures that the diffuser is not the only device responsible for dispersing light evenly.
The edge-lit design works well with a range of varied LED beam angles and doesn’t require lenses.
The back may be lightweight and won’t become hot as heat from the LED chips is dispersed throughout the frame. If necessary, the driver can be installed here.
Some producers lowered the price of edge-lit panels by using less expensive materials and assembly techniques, but this had an adverse effect on the panels’ quality. This primarily concerned the LGP. Some manufacturers now employ polystyrene (PS) LGPs; however, if UV stabilisers are not added, they may yellow with age, causing the center of the panel to become dull while the outside stays brilliant. Furthermore, PS transmits light at a lesser percentage than PMMA.
Backlit LED panels have been made possible by technological advancements.
With the increasing efficiency of LEDs, the inherent thermal advantage of side-lit designs has diminished, while not completely eliminated.
Modern adhesives allow lenses to be firmly affixed to each LED to generate an even distribution of light without the chance of falling off, which was a drawback with certain older, less expensive back-lit panels. Lens production has also gotten more affordable.
Due to the increased prevalence, decreased cost, and increased effectiveness of micro-prismatic diffusers, the dual function of the LGP/diffuser combo is no longer necessary.
Back-lit panels are thought to be more efficient since cheaper edge-lit panels employed LGPs with little light transmission; by contrast, back-lit panels completely eliminate the LGP.
Back-lit panels are becoming just as popular in the lighting industry as edge-lit panels. Although we offer both types in our product line at NVC, we have determined that edge-lit is only slightly superior. This is because the driver finds the back of the panel to be the most convenient location, and we want the driver to stay as cool as possible because we give guarantees of five and seven years.
What issues do low-cost back-lit LED panels have?
Their lack of LGP makes it feasible to create back-lit screens at a reasonable cost. Because of this, several manufacturers market back-lit panels as an affordable choice.
This is the thing to be cautious about.
Use of LEDs is inadequate. When there are insufficient LEDs—usually 36 or fewer—high current must be applied to them in order for them to provide the necessary amount of light. This is less efficient than designs with more LEDs (LEDs operate best with low driving currents), produces more heat, shortens the LEDs’ lifespan, and accelerates the degradation of lumens.
body plastic. Superior backlit panels have a metal frame. As a heat sink, this works better than a (less expensive) plastic body. In order to prevent further reduction in the lifespan of LEDs, the heat they produce must be released.
The spread of light does not overlap. Every LED in a high-quality back-lit panel has its own lens, and those lenses are made in such a way that the light from each LED overlaps the light from the LEDs next to it. In the event that one LED fails, this will result in a uniform lighting effect and some resilience. Low LED counts and poorly designed lenses are likely to reduce LED overlap and raise the possibility of bright and dark patches on the front of the fitting.
Are the lenses securely positioned? We’ll have to wait and see, but there’s a chance that the heat from the LEDs and the cheap glue application will lead to the lenses falling off. Uneven light distribution and perhaps equal glare will be the outcome.
Built-in driver. Building the driver into the body allows manufacturers to save money, but there are a number of disadvantages. In the event of a malfunction, it cannot be changed, and there are no dimming or emergency choices. It’s a rather rigid method.
Examine the frame’s corners. A noticeable seam will be seen on the less expensive panels.