Types of LEP flashlight modules
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Mirror-type LEP module
Following the era of incandescent bulb flashlights, LED flashlights marked a big shift, quickly establishing as the preferred choice for flashlight manufacturers. The improvements of LED flashlights had modest advancements, characterized by small increases in luminosity, better heat dissipation, and later also improved color rendering properties (CRI = Color Rendering Index).
However, a major change occurred in 2018 with the introduction of the laser-based flashlight, the Weltool W3. This was a noteworthy change in the world of flashlights but was hampered by several factors. The main factor was the initial cost, and secondly the unfamiliarity of users with this technology. Especially because of the use of lasers.
Soon after the Weltool W3, Acebeam introduced the larger Acebeam W30, with a significant increase in beam intensity, and therefore beam distance.
As the sole LEP module on the market (produced by another company, namely Blue Lake Light) other brands started incorporating these modules as well. However, they were all being classified as Laser 3B flashlights and therefore prohibited in specific regions and countries. This was the main reason why specific flashlight models were hard to get in certain countries.
These LEP modules had a blue laser projecting its illumination onto a mirror. This reflected the blue laser light onto a layer of phosphor or fluorescence, changing its color, into a white-ish beam. A convex lens is then used to widen the beam and make the beam look like an ordinary LED flashlight. The module is named WP-RX, and therefore Jetbeam included that in some of its flashlight model names as well.
This technique can be sensitive to chromatic aberration, resulting in color shifts inside the beam. This is often noticeable at close distance, where a blue-ish ring surrounds the beam. But it's not always visible, and one of the nicest beams we encountered on LEP flashlights was on the Acebeam W30, which used this particular module.
As of 2023, the mirror-type LEP flashlights are still the farthest shining type of modules. This can be seen in the Weltool W4 PRO.
Below, you will find images of the mirror-type LEP module. In the center of the module, you can see a little triangle-shaped object, which is the mirror.
Shine through type LEP module
With LED technology still advancing bit by bit, the LEP modules also have seen changes and improvements. The shine-through modules are another advancement in flashlight technology. In this LEP module, the laser is positioned behind a layer of phosphor, and unlike the traditional mirror-type modules, where the laser reflects off a mirror, these modules shine their laser directly through the phosphor layer. The emitted light then passes through a small domed lens that further widens the beam, making it much more practical.
With the laser directly behind the phosphor layer, the entire module is significantly smaller and can be used in much smaller flashlights. At the moment, the smallest flashlight this type of module is used in an AA-type flashlight. I would not be surprised to see it advance even more and end up inside AAA flashlights.
Getting rid of the plastic shell, the shine-through modules have much better heat dissipation. This results in a more stable beam output throughout its battery life. And on top of that, they can be screwed inside the flashlight, which could potentially also replace an LED module. A good example of that is the module used in the Maratac LEP DX Reach Rev 2.
The benefits of a shine-through module:
- More compact
- Easier and cheaper to produce
- Fewer materials necessary
- Can be used in much smaller flashlights, even as small as an AA-type flashlight
- Better heat dissipation
- Can be implemented in removable LEP modules, making it a better alternative than the Mirror Type module
Laser diode inside
Translucent phosphor
Other type LEP modules
To advance even more, this technology is also used by several car manufacturers, including BMW. And laser-based light sources are likely going to expand to more industries, and eventually even in home lighting.
Besides the different industries, BL Light has made several extreme versions as well, that don't fit in normal handheld flashlights, but only larger flashlights. This include the WP-NR1-UNI used in the Acebeam W50.
