MENTOR have added multiple array versions to their range, and all of the engineers I have shown rear-mounted samples to were very impressed. OK, they are not going to change the world but they are a clever concept that is highly practical and do enhance optical quality. However if you need IP68-rating, look elsewhere – by definition rear-mounted versions cannot deliver this (yet!).
As I described in my post of last April, conventional front-mounted light guides will by definition always have heads slightly larger than the enclosure’s hole, which results in not all of the head being directly illuminated by the LED. The advantage of mounting from the rear of the panel is that all of the light guide head is directly illuminated and this produces a markedly superior lighting effect.
MENTOR’s use of a flexible plastic chain to combine multiple elements into an array provides quick and simple mounting to save assembly costs. (Mechanical fixing is achieved via the radial compression of slightly over-sized rings moulded into the light guide body. The minimum recommended thickness of the front panel is 1.5mm.) The flexibility allows for tolerances between the holes in the front panel.
These arrays come in two versions. The spherical head type protrudes from the front panel, thus allowing a very wide angle of radiation, whilst the planar version delvers a flush mounting. In both versions no metalwork shields any part of the head so the entire light guide / light pipe head is directly lit by the LED. This results in visibly superior optical performance.
Lengths of 5mm and 45mm are available as standard with infinite variations in between available, often with little or no tooling costs. For custom versions it is possible to “mix and match” between 2 and 10 different variations of light guides from the 1256 series. As always with MENTOR, versions using a special diffusing material to produce a frosted effect are available, as is self-colouring of the light guides. The latter allows the potential illuminated colour to be shown even when the LED is in an “off” status.
More details are available here. Another innovative, cost-effective solution from MENTOR!
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