A look inside the iView Engine in LightCrafter4500

A few more pictures.

Removing the heat sink behind the LEDs:

Removing the LED boards:

Removing the DMD heat sink. You can now see the DMD placement on the light engine:

And finally, light engine without DMD, LEDs, and TIR prism:

PedroGelabert ,

I have some  questions,

1. What's the  reflectivity of the dichroic mirror in front of the red LED?

2. The dominant wavelength of the red LED is 617nm, right? is there higher wavelength red LED?

thanks,

He

He,

The transmission of the red dichroic mirror is roughly above 95% from 420nm to 550nm. It has close to 99% reflectance between 600 and 650nm. These values might change or shift due to variations in coating during production.

The transmission of the blue dichroic mirror is roughly above 95% from 510nm to 600nm. It has close to 99% reflectance between 400nm to 480nm. These values might change or shift due to variations in coating during production.

The light engine has as Red LED the OSTAR LE A A Q9WP from OSRAM with a dominant wavelength of 617nm. In why Q9WP package, i am only aware that OSRAM only produces amber light. You can find more information of these LEDs in this link.

Best regards,

  Pedro

This is very interesting insight in the LC 4500 optics.

One important question for me is whether there is a way to lock the focus setting reliably once it is focussed to the correct distance.

Regards

Erik

The focusing mechanism is a pin that rotates in helix fashion around the focus optics. As you can see in the attached image, the pin has a hole that could be used to hold/tie it in place. There is also another screw hole in the focus barrel that can be used to hold the focus mechanism in place. 

Hi Pedro,

I have a question concerning the light engine and the illuminance of the 3 LEDs. Could you specify how were the values provided on pages 23-24 of the User manual determined? I'm referring to the graphs of LED illuminance. Is this illuminance at the output of the light engine, or the illuminance of the LEDs without any optics? If the latter, is there any data available on the effective illuminance (or better yet, on the irradiance) at the output of the system for each color?

Thanks,

Zuzanna

Yes, the illuminance is at the output of the Light Engine. For illuminance at the output of each LED, refer to OSRAM data sheets. The LEDs are at the end of this thread.

Thanks a lot Pedro for this info and also your reply concerning the noise. I think the link you posted refers to the LEDs in the first LigthCrafter though, right? There are other LED part numbers listed above in your original post concerning the light engine, are these the ones for the 4500 model?

best

Zuzanna

Also, just to make sure I understand correctly: the irradiance values are in lux, ie in lumens/sq meter, so were they measured for an image at 1m, ie of 33.3'' diagonal size (I'm going by the iView specs here)? I'm trying to recover information about the total light flux in fact, is that the way to go? I get an image area of 0.324 sq meters at 1m, so that gives me for ex. 110*0.324=35 lumens max for the blue LED. Could you confirm or else specify for what total image size the values were taken?

Thanks a lot!

Zuzanna

Zuzanna,

Sorry about that. You are correct that link was the 0.3" LightCrafter LEDs. The LightCrafter 4500 OSRAM LEDs are:

• CG Q9WP - Green
• LE A Q9WP - Red
• LE B Q9WP - Blue

You can find the data sheets here.

Hi Pedro,

I have another question concerning the light engine of the LightCrafter 4500 (we should be receiving the one we ordered soon and are planning how to integrate it in our microscopy system) - is the illumination of the chip telecentric?

best

Zuzanna

Dear Pedro,

How easily can you replace the LEDs in the light engine with different ones? I understand that the filters need to be changed if this is done but I'm more interested in the practical aspect of changing the LEDs.  And what about the casing of the light engine, is it made out of aluminium or is it plastic?

I sent you a friend request  and I was hoping if you could give some advice in our imaging project.

Best,

Kari

Hi Pedro,

Could you possibly provide data for optical elements (e.g. focal length of each lens)? Recently we have purchased a DLPLCR4500EVM., but for our research application we need to replace current optical elements (from LED to DMD) with UV compatible ones.

Thanks,

Hamid

Hi Pedro,

Can I have optical element data inside DLP LightCraft 4500 EM?

Best,

James

James,

The light engine in LightCrafter 4500 was designed by the DLP Design House iView Limited. You would need to contact them for entail information on their light engine. Contact information is on the link. 

Hi, 

How to align the three beams?

The final beam after DMD without projection lens is tilted upward some degree. How to make it correct, i.e no tilt ?

I think that there is tip-tilt mirror before DMD (after lenslet array), so can I use this mirror?

Many thanks in advance,

James

James,

This upward tilt is by design.  This projector engine is designed with "100%" offset.  This means that the bottom (of the projected image) is along the axis of the projection lens.  There is no adjustement designed into this engine to make the center of the image align with the optical axis of the lens.

This allows the projection engine to lay flat on a table and project onto a wall without being clipped by the table.

Typicaly the three beams are aligned well enough to illuminate the DMD and do not contemplate alignment for use without the final imaging (projection lens).

Fizix

Dear Pedro,

thank you so much for your excellent analysis.

I have a small question about the DLP4500: is it possible to operate the device after removing the objective (as in second photo)

I would need to keep the illumination path and the TIR prism, but I would then design custom optics for the projection path. Is it possible in this case to use the electronic boards to control the system?

Dear Michele,

You can remove the projection optics easily since it is only attached to the light engine with 4 screws. We've done this already in our lab and we've also modified the baseplate in order to have the DMD in the optical axis.

The Lightcrafter will work 100% normally with or without the projection optics.

Best,

Kari

Dear Kari,

thanks a lot for the quick answer!

Best,

michele

Michele,

Yes, the electronics only drive the LEDs and the DMD. All the optics can be removed and the electronics will drive the DMD. You can place a jumper on J30 to turn off the LED driver if you are not using it. If you intend to change the projection optic, but keep the illumination portion that also will be fine. Note that there is a 100% offset in the projection, so you will need to account for that in your optics.

Best regards,

  Pedro

I am trying to follow these instructions to remove the default LEDs and replace them with different ones. I am finding a lot of resistance and glue with every single part that your pictures show you dismantling easily; is there a safe and efficient way to take apart the light engine in the presence of all of the glue?

Dear Artimus,

We demonstrated our new LC4500 control board at Photonics West last week. Among other features, it supports a cable length up to about 250 mm (we've not tested longer than that yet). Please go to our contact page at KeynotePhotonics.com and we can send you some information... we've not had time to put it on our web-site yet. 

Nevin,

The LED are mounted on the Light Engine with small custom boards. When you swap LEDs, you need to consider how they are driven:

• same operating voltages and currents from the LED driver
• size of the LED and how it is coupled to the system (etandue)
• dichroic mirrors and how they pass or cut the wavelengths of lights produced by the LEDs
• wavelengths of light supported by the DMD. Note that the DLP4500 data sheet has a 420nm low end limit and power level restrictions

Hi, this is extremely helpful, thank you! I was wondering how you safely removed the adhesive from the DMD enclosure - is it easy to remove? Does it require any tools, or does the adhesive break easily?