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Thread: Seeking Casio's without diode block

  1. #21
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    Exactly because of what you are saying here it is a mystery for me how the DLP can ever be used for projecting laser, as the beams will only be "nice" at the focal plane.
    I did think a bit about it after you asked about the Cas..s. I just can't imagine that DLP's can be useful for laserists other than for holographic films.
    Despite my discouraging post, I have high hopes for these MEMS. Here is why. They have rated power handling something like 25W/cm2. That's 50W for their .95" HD chip and that's spec and when do we stay strictly spec. At spec and with balanced white light that's 35,000 lumens and that's just about the output of the world's most powerful DLP based projectors. The problem the manufacturers face is that they are limited to non-coherent (ultimately) light sources. We are not.

    I have an Acer HD projector that outputs 4,500 lumens and when using the Pangolin video presentation option I can display any laser show through video and RGB projector side by side The 100,000KPPS DLP blows the laser away. This is a throughput 3,000 times what the laser can produce, but...BUT the video is very pale by comparison. Based on experiments the video is about as bright as a 500mW combined output laser projector.

    The brightness could be increased further, much further than even the effective 35,000 lumens would suggest because unlike the continuous illumination (yes, I know about dimming) of a typical HID video bulb the laser would only heat when it was on. Modulated laser illumination would make the color wheel unnecessary and polarized laser light would substantially increase the contrast of the video image not to mention that alternating polarization would enable 3D.

    So, rather than try to emulate a monolithic galvo set, a laserist might want to turn an average video projector into a powerhouse that complements a typical RGB laser show with an ultra high bandwidth source. Problem is I'm kinda busy right now, but you see why I'm excited about these possibilities and why I asked what you were thinking about doing with these Cas....s?

  2. #22
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    Quote Originally Posted by planters View Post
    Problem is I'm kinda busy right now, but you see why I'm excited about these possibilities and why I asked what you were thinking about doing with these Cas....s?
    Planters, can you outline the experiment that you would do if you had the time?
    1) Would you shape the light into a rectangular pattern for a effective output?
    2) How would the setup differ from the way a ca**o work from box
    I must admit, that I still haven't fully understood what the DLP can do for the laserist.
    But if I understood, then I might just try out the experiment. I now have 37 pj's, so I think that I can afford to sacrifice one or two to the greater good :-D
    Best regards
    Jan Thogersen

  3. #23
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    This may take a little more serious thought and forgive me if I state the obvious.

    You first need to find out how to access the DLP in a way and from an angle that closely duplicates what the manufacturer intended while not preventing the original electronics from controlling the chip.

    You need to access a comp based program that will produce simple fixed (still) input video patterns.

    You need to identify the signal that controls the alternating color sources to the chip and in a non-HID projector this should be fairly simple.

    The illumination pattern can be approached in a number of ways and I would probably start with a monochromatic array with say one or 4 of the 445nm diodes. These could be collimated and adjusted to cover the DLP, but as an initial proof of concept you don't even have to concern yourself with the whole array, just collimate the beam and adjust it to shine on one corner and modulate the laser driver with the C**O's blue channel signal. It may turn out the imaging optics of the projector will want something other than a parallel light input, but this too should be pretty easy to adjust to once you set this up.

    You might want to keep each projector monochromatic to simplify the color adding/dichroic optics and further increasing the power handling capacity of the DLP,. This would also allow a color to remain on rather than forcing it to time share with the other lasers and for lasers that don't modulate well (ions and some DPSS lasers) this could be another advantage.

    Let me know what you think?

  4. #24
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    ... I'm modifying the C***o-DLP-beamers for 'lampless' mode, so I can insert an UV-LED or BluRay laserdiode as lightsource for UV-Resin-3D-printing.

    When finding some time, I'm planning to focus a pulsing N2-TAE-laser with 200ps short pulses with 400kW @337nm (but 'averaged' to <1mw over time) across a DMD-chip to test, if the energy density in the focus (maybe 1x1 or 2x2mm) is enough to remove material ... and if the DLP-image is detailed enough in this 'reduction' ...

    Viktor

  5. #25
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    Quote Originally Posted by planters View Post
    Let me know what you think?
    I think we need a short Skype session if you are up for it. I think that's the most effective way to evolve the idea.
    Best regards
    Jan Thogersen

  6. #26
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    Hi Jan.

    Cool project. :-)

    Do any of you remember in the late 90's, when schneider laser came with the first solid-state laser white light system. They had a Carl Zeiss block with a fiber cable connected from the laser.
    I did see the system run with video projection, at a fair trade in berlin around 96-99 (i think). Don't know how them made the video projection. But it was really bright and nice detales at that time :-)
    Can be it's was made with the a rot polygon scanning or gavlo ?

    But still the res. would be quite low.

  7. #27
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    ... IIRC Schneider used polygon mirrors, so displayed the image similar to the line-scanning in CRT-tubes with v-sync+h-sync modulation -- DMD-chips weren't on the radar then ...

    Viktor

  8. #28
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    Quote Originally Posted by Laserpower View Post
    Cool project. :-)
    Hi Poul! Thanks, but the idea is Planters. My just curious :-)

    Quote Originally Posted by Laserpower View Post
    Can be it's was made with the a rot polygon scanning or gavlo ?
    But still the res. would be quite low.
    As VDX says, the scheme was a video buffer, a rotating polygon for x axis movement and a galvo for y axis movement.
    Tons of patents was made, none of which is used today I guess. That technology was outdated even before it got mature. Sad actually.
    Best regards
    Jan Thogersen

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