Page 1 of 3 123 LastLast
Results 1 to 10 of 23

Thread: Interesting Layout

  1. #1
    Join Date
    May 2006
    Location
    Native Floridian
    Posts
    3,127

    Default Interesting Layout

    Just kinda noticed that the folks over at LaserFreak forum, have some very interesting layouts to thier projectors. Seems they are not using 45 degree dichro's, I wonder how much benefit there is to doing this:




  2. #2
    Join Date
    Jan 2007
    Location
    Cupertino, California
    Posts
    2,130

    Default

    That's a way of getting the heights of the lasers to match us with 2 mirrors instead of one.
    CLICKY!!!

    Admin: In the immortal words of Captain Planet: YOU HAVE THE POWER
    Admin: (To quit being a bitch)

  3. #3
    Join Date
    May 2006
    Location
    Native Floridian
    Posts
    3,127

    Default

    That's not really what I'm refering to. Its where the beams come together on the bench are at very unique angles prior to going to the scan head.

  4. #4
    Join Date
    Apr 2006
    Location
    Orlando, FL - USA
    Posts
    1,770

    Default

    Dichros are not exclusively optimized for 45-degree (mechanical) operation. Some are actually optimized for the "zero angle". In fact, in my own projector that uses a HeNe and Argon, I use a dicrho with nearly zero-angle incidence. There could be some throughput benefit, depending on the dichro. (In my case, there is.)

    Now, with that having been said, that may not be the reason why those particular projectors used non-45-degree arrangement. It could be space reasons or even ignorance...

    With non-45-degree incidence, polarization becomes much more tricky. In my case, I was able to rotate the (round) HeNe to optimize the polarization. That's not easy with square lasers that have mounting flanges...

    Lesson (whether it applies here or not): Just because someone else does something, doesn't mean that even they know the consequences!! Don't assume that if someone does something different from you, that they are necessarily smarter than you. After all, how many times was the (extremely poorly designed) Laser Media LM22SDA Scanner amp duplicated by people who thought that surely, Laser Media must know what they are doing?

    Best regards,

    William Benner

  5. #5
    Join Date
    Jan 2008
    Location
    Stockholm, Sweden
    Posts
    799

    Default

    I see one apparent drawback with this setup. They're adding the blue light first, with an extra mirror. Since every mirror represents a small loss you'd want to add blue last like is typically done in our 45° setups. Assuming that 5% is lost on every mirror (which might be a bit high) you'd end effectively up turning that 100 mW blue into a 86 mW, and that's before the galvo mirrors!

  6. #6
    Join Date
    Dec 2006
    Location
    Netherlands
    Posts
    983

    Default

    A lot of the guys at the Laserfreak forum are using dichros optimized for 22.5 degrees. I believe it was HB laserkomponenten that sold these.
    In my projector I chose to add red as the last color because it has the lowest brightness. Although blue is more expensive per mW, adding red last gives the most balanced white output in my case. Here this person might have had the same line of reasoning.

  7. #7
    Join Date
    Feb 2007
    Location
    Delaware USA
    Posts
    794

    Default LM22SDA

    Quote Originally Posted by Pangolin View Post
    After all, how many times was the (extremely poorly designed) Laser Media LM22SDA Scanner amp duplicated by people who thought that surely, Laser Media must know what they are doing?

    Best regards,

    William Benner

    Hey Bill,

    Whats so bad about these Laser Media Amps? I have two projectors
    that still use these amps. What should I look out for as so, I don't damage the G120D's?

    Thanks,

    Mark

  8. #8
    Join Date
    Jan 2007
    Location
    Sheepsville, Wales, UK
    Posts
    3,406

    Default

    The Edmund Optics blue dichro I have is absolutely pants at 45 degrees. Put it close to 90 to the beam and its brilliant with very little transmission. In contrast their red dichro is mega at 45 - but get it a little off and you loose power.
    Hopefully this week I will be doing some real testing of the dichros I have from Bridge at laserwave. In initial tests it is very clear they transmit much less than EO ones (of the colour they are supposed to reflect) and they are extremely insensitve to angle.

    Rob
    If you need to ask the question 'whats so good about a laser' - you won't understand the answer.
    -----------------------------------------------------------------------------------------------
    Laserists do it by the nanometre.

    Stanwax Laser is a Corporate Member of Ilda

    Stanwax Laser main distributor of First Contact in UK - like us on Facebook http://www.facebook.com/FirstContactPolymerCleaner
    www.photoniccleaning.co.uk

  9. #9
    Join Date
    Apr 2006
    Location
    Orlando, FL - USA
    Posts
    1,770

    Default

    Quote Originally Posted by ImageLight View Post
    Hey Bill,

    Whats so bad about these Laser Media Amps? I have two projectors
    that still use these amps. What should I look out for as so, I don't damage the G120D's?

    Thanks,

    Mark
    The LM22SDA is probably the worst amp ever made for G-120s. There are lots of problems with that design. One problem is that the position demodulator is only single ended, and also, the way they did it, if you key-up a walkie talkie or even bring a cell phone anywhere near those amps, it will drive the scanners crazy.

    Another thing -- there is no current limit inherent in that design. On the G-120, if you drive more than 2.25 amps peak current into that scanner, you will demagnetize it (eventually).

    There have been many a demagnetized G-120s, and also many shorted position diode rings that resulted from the LM22SDA. It's basically a scanner killer. (Not to mention, you barely get 12K out of these amps...)

    Best regards,

    William Benner

  10. #10
    Join Date
    Jan 2005
    Location
    Norway
    Posts
    1,303

    Default

    I think this setup is the best..
    Quick and simple..
    And you can adjust the height on each laser with just one mirror !
    This is the setup I use now : (see attachment)
    Attached Thumbnails Attached Thumbnails MediaLas_beam-alignment.jpg  


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •