Question about the development of "edge-lit" LED lamps

[treebev5]

Hello,

I am quite sensitive to light, and so I tend to prefer lighting in which the direct filament is blocked from my line of sight (i.e. I can't see it directly even in my peripheral vision).

One thing that looks promising that I've become aware of only recently is so-called "edge-lit" or "side-lit" LEDs. In these LED assemblies, the diodes are positioned perpendicular to the path through which the light is emitted. There are some materials that help direct the light out the right way--think of a periscope, or an illuminated Exit sign.

I will link to some examples below. Please note I don't endorse any of these lamps. My main concern is identifying <i>when</i> an item uses an edge-lit LED. Do you think they will always mention so when they are? They all seem to have a circular or square-like diffusion plate, as oppose to the more narrow ones I am used to. But often the manufacturers don't include a figure showing the parts of the light assembly separated.

Incidentally, I find it kind of annoying that a lot of LED lamps mention that they have some "eye care" technology, when really all that means is that they've taken steps to address some of the previous shortcomings of LEDs. I love LEDs, especially their prospects to create very light assemblies for use in industrial design and survival, but it kind of reminds me of when a polyester garment says it has "odor-fighting" properties. After buying a couple of these, I've come to realize that they just want to allay your concern that said garments will stink after one wear (and they invariably do).

Anyway, LED lights are much better than polyester at their intended purpose, but I just wanted to know why these are only making their way into lamp technology now. Is it just advances in optical materials? I know that cell phones are starting to come with "periscope" lenses, so that the chamber the light flows down is parallel to the phone itself, which will allow for greater focal lengths (sorry if I'm misusing some terminology).

Thanks.

Some examples for reference (these are non-affiliate links):

1) Lume Cube Edge Desk Lamp

This one looks like the fanciest, but it apparently hasn't been shipped yet, and is missing dimensions and lumen output information.

2) Eyocean Desk Lamp

3) Niulight LED Desk Lamp

Suspected Edge-Lit Lamps (does not explicitly say, but LEDs are shown to be perpendicular to housing):

1) Saicoo LED Desktop Lamp with Large LED Panel

2) The others appear to be clones of number 1

 

[uk_caver]

I can understand that the lights you linked to might have advantages due to having a large emitting area (reducing shadows, etc), but thinking purely of never having a light source visible in peripheral vision, wouldn't a small LED source sunk inside a shield actually be better than a large flat (and rimless) source?
The LED light I use for close-up work on my workbench is a homemade one which in terms of geometry is roughly equivalent to a miniature version of a large old-fashioned desklamp using a small bulb, and with that setup, I can have the light brightly lighting what I'm working on while having no line of sight between my eyes and the LED.

 

[treebev5]

I can understand that the lights you linked to might have advantages due to having a large emitting area (reducing shadows, etc), but thinking purely of never having a light source visible in peripheral vision, wouldn't a small LED source sunk inside a shield actually be better than a large flat (and rimless) source?
The LED light I use for close-up work on my workbench is a homemade one which in terms of geometry is roughly equivalent to a miniature version of a large old-fashioned desklamp using a small bulb, and with that setup, I can have the light brightly lighting what I'm working on while having no line of sight between my eyes and the LED.

I completely agree. That sounds ideal. I think the idea of making it indirect is that it approximates a single source of lighting instead of getting the little beads, but I prefer lamps where the filament is sunken well within the shade. I do see LED lamps like that--they are referred to as "workshop lights". They seem a little expensive but they do look like they would be a lot better.

Could you link me to an example of your style of lamp? Do you know how many lumens it is, and it comes in a non-clamp format? For example, like one of those swing-arm lamps that uses a bolt to provide leverage, or a weighted base.

Thanks.

 

[uk_caver]

I'm afraid that I don't know anything about commercial LED desklamps - my homemade one is just a ~400lm LED emitter glued to a PC heatsink, with the plastic holder for a TIR optic (minus the TIR optic itself) surrounding the LED, and a conical shield of aluminium foil wrapped around the holder, with the front of the cone cut at a slant so that I can have my eyes further 'in front' of the LED (closer to the most brightly-lit area of the beam) while staying in the 'full shadow' area (see picture). If the cone didn't have a slant, as soon as my eyes were 'in front' of the cone, some of the annoyingly-brightly-lit inside of the cone would be potentially visible.
I happened to have a convenient wooden shelf on my workbench, so I just used a piece of metal gooseneck to flexibly attach the heatsink to the shelf.
If I was to make a more mobile version, I'd probably use an old weighted-base gooseneck desklamp as a base.

 

[treebev5]

I'm afraid that I don't know anything about commercial LED desklamps - my homemade one is just a ~400lm LED emitter glued to a PC heatsink, with the plastic holder for a TIR optic (minus the TIR optic itself) surrounding the LED, and a conical shield of aluminium foil wrapped around the holder, with the front of the cone cut at a slant so that I can have my eyes further 'in front' of the LED (closer to the most brightly-lit area of the beam) while staying in the 'full shadow' area (see picture). If the cone didn't have a slant, as soon as my eyes were 'in front' of the cone, some of the annoyingly-brightly-lit inside of the cone would be potentially visible.
I happened to have a convenient wooden shelf on my workbench, so I just used a piece of metal gooseneck to flexibly attach the heatsink to the shelf.
If I was to make a more mobile version, I'd probably use an old weighted-base gooseneck desklamp as a base.

Wow, that's neat. If you don't mind my asking, what motivated you to construct your own LED lamp? Is it just that you wanted to built it as a project, that it's cheaper, or for another reason?

 

[uk_caver]

I built it a long time ago (when Cree MC-Es were new, so probably around 2008-9), and I don't think there were many (if any) equivalent commercial lights available then.
The LED was left over from experimentation, with no other planned use, and back then, LEDs seemed to go from cutting-edge to semi-obsolete relatively quickly, so the effective cost was basically just a couple of ~$3 driver boards and the 12V PSU.
The mounting to the shelf works really well - with the gooseneck mounted horizontally on a shelf upright at around eye level, it's easy to pull down when needed, and push completely out of the way when not.
It typically runs all day (when not in active use, it's pushed up and acts as a useful uplighter), and it still seems to be going strong.
(Actually, having just checked the power draw, it's probably more like 600-700lm, rather than 400lm.)

 

[treebev5]

I built it a long time ago (when Cree MC-Es were new, so probably around 2008-9), and I don't think there were many (if any) equivalent commercial lights available then.
The LED was left over from experimentation, with no other planned use, and back then, LEDs seemed to go from cutting-edge to semi-obsolete relatively quickly, so the effective cost was basically just a couple of ~$3 driver boards and the 12V PSU.
The mounting to the shelf works really well - with the gooseneck mounted horizontally on a shelf upright at around eye level, it's easy to pull down when needed, and push completely out of the way when not.
It typically runs all day (when not in active use, it's pushed up and acts as a useful uplighter), and it still seems to be going strong.
(Actually, having just checked the power draw, it's probably more like 600-700lm, rather than 400lm.)

That's really cool, man. Got a pic? I want to make some sort of adjustable downlight that can be mounted on the side of a table using a photographer's fill light so I'd appreciate any pointers on how one goes about doing that.

I am still searching for side-lit LEDs, and it can be quite tricky to tell if a lamp has them. If they don't have a picture showing the LEDs in the assembly, I just assume it's back-lit and not edge-lit.

The latest LED advancement that I've become aware of is COB (chip on board) LEDs, which apparently allow a greater density of diodes than SMB (surface mount diode) assemblies. They look pretty cool, like they might lead to a greater singularity in consumer LED lighting.

 

[Dave_H]

Not sure this will necessarily help you; but I have opened up a number of small LED ceiling fixtures, and found at least one smaller square ones uses LED strip edge-mounted. makes light output quite even. Some of these plug directly into E26 socket, but usually the round ones with forward facing LEDs. It's a long shot but maybe something small like this could work for you.

Dave

 

[jtr1962]

Not a desk lamp but I bought a Viltrox LED video light panel on Amazon a few years ago. Definitely edge lit. Also 95 CRI and CCT is adjustable from 3300K to 5600K.

I noticed all the desk lamps you linked to also have adjustable CCT. It's great this is common nowadays. Everyone gets to pick whatever CCT they like best.

 

[JustAnOldFashionedLEDGuy]

Edge lit ceiling lights have high glare as too much light is emitted at a shallow angle wrt the ceiling right into your eyes. Inset lights are much better.

 

[datsunscott]

Looking for some miniature tiny "hooded" downward shining led lights. I have seen windshield washer lights with led but really doesnt fit my need. license plate bolt lights stick out too much. I just need a tiny surface mount close to flush that blocks light one direction (up) and shines the other way (down). preferably bblack platic but I could paint them. I am looking for a "smooth" light so nothing catches on it. Anyone suggestions?