Light focusing tube

[Klaus Kragelund]

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

 

[John Robertson]

On 2019/08/12 2:21 p.m., Klaus Kragelund wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

One trick is to literally cut the dome off the LED (if it has a dome)
and polish the surface flat. This makes a nice bright LED spot instead
of the diffuse glow from the dome.

Or get a lens from Edmunds if you are doing a number of these...

John :-#)#

 

On Monday, 12 August 2019 23:43:18 UTC+2, John Robertson wrote:

On 2019/08/12 2:21 p.m., Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus


One trick is to literally cut the dome off the LED (if it has a dome)
and polish the surface flat. This makes a nice bright LED spot instead
of the diffuse glow from the dome.

Nice trick

 

How small a spot?

Cheers

Phil Hobbs

 

On Monday, 12 August 2019 23:48:51 UTC+2, pcdh...@gmail.com wrote:

How small a spot?

The emitting LED chip is 1mm2, the receiving LED has a housing of 1mm2, but a chip of about 0.1mm2. So I would be happy to have the spot of just less than 5mm2. I am ballparking here, I would like the spot to be bigger than the receiving LED, so that I can have production equipment that does not need to be top notch to "cover" the receiving LED in photons

Cheers

Klaus

 

[Rick C]

On Monday, August 12, 2019 at 6:15:09 PM UTC-4, klaus.k...@gmail.com wrote:

On Monday, 12 August 2019 23:48:51 UTC+2, pcdh...@gmail.com wrote:
How small a spot?


The emitting LED chip is 1mm2, the receiving LED has a housing of 1mm2, but a chip of about 0.1mm2. So I would be happy to have the spot of just less than 5mm2. I am ballparking here, I would like the spot to be bigger than the receiving LED, so that I can have production equipment that does not need to be top notch to "cover" the receiving LED in photons

Does this require nothing in between? Can you use a light pipe? They are common to illuminate front panels from LEDs on the board behind. If the path is straight the light pipe just becomes a plastic cylinder. They make them in many shapes and sizes with various attachments.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[George Herold]

On Monday, August 12, 2019 at 5:21:25 PM UTC-4, Klaus Kragelund wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

Huh, we use to electroplate copper onto SS cones... very long tapers,
a few degrees.. to focus FIR (say 10-100 um) onto a detector.
One grad student designed a parabolic reflector..
that did better. This is not for imaging, but just gathering as many
photons as possible.

What about a lens?

George H.

 

On Mon, 12 Aug 2019 14:21:21 -0700 (PDT), Klaus Kragelund
<klauskvik@hotmail.com> wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes ?

Regards

Klaus

Are you trying to change the way the LED looks, or are you trying to
project a spot onto some distant surface?

Focusing is usually done with a lens.

 

[Jasen Betts]

On 2019-08-12, Klaus Kragelund <klauskvik@hotmail.com> wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

Which LED, how small?

Can you use an SMD LED instead?

--
When I tried casting out nines I made a hash of it.

 

[Martin Brown]

On 12/08/2019 22:21, Klaus Kragelund wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

Why not use an LED with a much narrower viewing angle?
15 degrees is relatively common eg

https://www.rapidonline.com/truopto-ospg5111a-vw-5mm-3-3v-green-led-high-brightness-15-55-1816

At that low beam divergence it might already be good enough on its own
or with a small lens in front.

> I was thinking about light reflective mylar, but am open to suggestions?

The other way is to surround the detector with a non-focussing flux
concentrator. But 120 degrees focussed down to a dot is a bit of an ask
- small angle approximations don't hold so you are into exotic curves.

Such things can be done there are a handful of eyepieces now with AFOV
of 100 degrees or more but I don't think you will like the price.

https://telescopes.net/store/eyepieces/category/eyepieces-by-field-of-view/100-120-fov.html

This is for test equipment, so anything goes 😊

Short length of clear Perspex rod clear epoxy onto the water clear LED.


--
Regards,
Martin Brown

 

[piglet]

On 12/08/2019 10:21 pm, Klaus Kragelund wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

A long metal tube shiny on the inside?

piglet

 

[TTman]

On 13/08/2019 10:04, piglet wrote:

On 12/08/2019 10:21 pm, Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle
of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus


A long metal tube shiny on the inside?

piglet

I used black delrin with a 5 mm bore to produce a narrow beam for laser
tag IR...

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

On Tuesday, 13 August 2019 10:43:37 UTC+2, Martin Brown wrote:

On 12/08/2019 22:21, Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

Why not use an LED with a much narrower viewing angle?
15 degrees is relatively common eg

https://www.rapidonline.com/truopto-ospg5111a-vw-5mm-3-3v-green-led-high-brightness-15-55-1816

At that low beam divergence it might already be good enough on its own
or with a small lens in front.


Yes, could help to find an alternative LED with more focus from the get go

 

On Tuesday, 13 August 2019 09:31:26 UTC+2, Jasen Betts wrote:

On 2019-08-12, Klaus Kragelund <klauskvik@hotmail.com> wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

Which LED, how small?

Can you use an SMD LED instead?

I cannot use a smaller LED. This one is a 5W++ one, so has a certain size

 

On Tuesday, 13 August 2019 02:31:50 UTC+2, Rick C wrote:

On Monday, August 12, 2019 at 6:15:09 PM UTC-4, klaus.k...@gmail.com wrote:
On Monday, 12 August 2019 23:48:51 UTC+2, pcdh...@gmail.com wrote:
How small a spot?


The emitting LED chip is 1mm2, the receiving LED has a housing of 1mm2, but a chip of about 0.1mm2. So I would be happy to have the spot of just less than 5mm2. I am ballparking here, I would like the spot to be bigger than the receiving LED, so that I can have production equipment that does not need to be top notch to "cover" the receiving LED in photons

Does this require nothing in between? Can you use a light pipe? They are common to illuminate front panels from LEDs on the board behind. If the path is straight the light pipe just becomes a plastic cylinder. They make them in many shapes and sizes with various attachments.

Light pipe is a good idea. Don't know how much light is lost in a pipe, found no numbers in the datasheets I looked into

Regards

Klaus

 

On Tuesday, 13 August 2019 02:10:32 UTC+2, George Herold wrote:

On Monday, August 12, 2019 at 5:21:25 PM UTC-4, Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

Huh, we use to electroplate copper onto SS cones... very long tapers,
a few degrees.. to focus FIR (say 10-100 um) onto a detector.
One grad student designed a parabolic reflector..
that did better. This is not for imaging, but just gathering as many
photons as possible.

What about a lens?

Lens could be an option, but has to be indifferent to the length from the object, so it is robust against production changes

 

On Tuesday, 13 August 2019 01:55:38 UTC+2, jla...@highlandtechnology.com wrote:

On Mon, 12 Aug 2019 14:21:21 -0700 (PDT), Klaus Kragelund
klauskvik@hotmail.com> wrote:

Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes ?

Regards

Klaus

Are you trying to change the way the LED looks, or are you trying to
project a spot onto some distant surface?

Project a spot

 

On Tuesday, 13 August 2019 11:04:13 UTC+2, piglet wrote:

On 12/08/2019 10:21 pm, Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus


A long metal tube shiny on the inside?

piglet

Yes, that is what I was looking for when talking about the reflective mylar

Maybe a problem with the extreme angles (120 degrees), that just bounces back and forth between the inner sides of the tube, and when it escapes the end of the tube it still has 120 degrees?

 

[George Herold]

On Tuesday, August 13, 2019 at 8:28:52 AM UTC-4, klaus.k...@gmail.com wrote:

On Tuesday, 13 August 2019 02:10:32 UTC+2, George Herold wrote:
On Monday, August 12, 2019 at 5:21:25 PM UTC-4, Klaus Kragelund wrote:
Hi

I need a light focusing tube, to turn a green led with viewing angle of 120 degrees down to a small spot

I was thinking about light reflective mylar, but am open to suggestions?

This is for test equipment, so anything goes 😊

Regards

Klaus

Huh, we use to electroplate copper onto SS cones... very long tapers,
a few degrees.. to focus FIR (say 10-100 um) onto a detector.
One grad student designed a parabolic reflector..
that did better. This is not for imaging, but just gathering as many
photons as possible.

What about a lens?

Lens could be an option, but has to be indifferent to the length from the object, so it is robust against production changes

Yeah I don't know of a lens that does that. If not a reflecting light tube,
then maybe a glass or plastic light pipe. (big fiber optic type thing.)
Can you butt the led to light pipe to detector, or does there need to be a gap?

George H.

 

[Steve Wilson]

Martin Brown <'''newspam'''@nezumi.demon.co.uk> wrote:

https://uk.rs-online.com/web/p/products/6656735/?grossPrice=Y&cm_mmc=UK-P
LA-DS3A-_-bing-_-PLA_UK_EN_Displays_And_Optoelectronics-_-Led_Lighting_Sy
stem_Components%7CLed_Reflectors-_-PRODUCT+GROUP&matchtype=e&pla-45746555
67267318&msclkid=1bc025289b3b137ab95b787a23b0b724&gclid=CPChlsf3_-MCFYMcG
wodW1oDNA&gclsrc=ds

Sorry about the wacky long URL. Google clip on reflector LED.

https://tinyurl.com/

https://tinyurl.com/yxs7bwkn