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Thread: Advice for 405nm Laser Polygon Mirror Scanning Device

  1. #1
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    Default Advice for 405nm Laser Polygon Mirror Scanning Device

    Alright I'm designing a laser scanning device that uses a polygon mirror motor found in laser printers.


    The laser beam must always be in focus to get the highest resolution scans, therefore all laser printers uses a "F-Theta" lens so that the laser beam
    focal point will always be in focus for the entire scanning surface. F-Theta lens used in laser printers are specifically designed for 1 axis laser scans only.


    Heres the problem, the F-Theta lens found in laser printers are not designed for the UV wavelength lasers such as 405nm. They originally use a different wavelength most likely infrared.


    I spent days searching on the internet to find a company/manufacturer that sells these 1 axis F-Theta lens and couldn't find any.
    Anyone here knows a company or maybe probably can tell me how I can make my own F-Theta lens used specifically for 405nm lasers?
    (Yes, I know many factors must be know such as the polygon mirror size and scanning distance etc... etc)


    I do not want to use the multi axis f-theta lens used with galvo scanning motors. I would like to use f-theta lens specifically for 1 axis scans.
    Have any other ideas how I can get the focal point always in focus throughout the entire 1 axis?


    Please view the attached picture so that you can get an idea what I am talking about.
    Also please do not mention about other people's project which is irrelevant to mine, I do not want to use a transparent prism.


    Thanks.
    Attached Thumbnails Attached Thumbnails Laser_unit_dell_p1500_print.jpg  


  2. #2
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    Default double threads

    did you mean to make a second identical thread?
    if not you might want to dele one of them-- hope you have a great new year-hak
    Last edited by hakzaw1; 12-26-2020 at 23:20.
    BEYOND-FB3/APC40Mamba Black(clone & currently on loan) 2X 5paghetti & 2 I-Show 2X KGB 1000mW 532 DT40K (pair)XFX 1300 RGB full color RGB 30K DIY 3.5WRGB work in progress et al..assorted ttl chi-jectors--LOTS of LUMIA DIY pjs-
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  3. #3
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    Default

    Quote Originally Posted by hakzaw1 View Post
    did you men to make a second identical thread?
    if not you might want to dele one of them-- hope you have a great new year-hak
    Yes, wanted to see if anyone in those threads would know something about what I needed. But anyhow, how would I delete the thread at the "Laser Displays, Shows, and Scanning" forum?

    Thanks.

  4. #4
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    Default no worries mate

    -- I made a double threads once..by error but-- its one of those unwritten 'rules'.. like two posts in a row.
    no big deal-
    Glad to see this thread- I want to know more about the stuff I have harvested from dozens of printers and other places.
    I have gotten one mirror array to spin- it makes a very nice flat beam- good for liquid sky. but not much beyond that..too little time for too many projects tick tock)
    got tons of FSMirrors.. a life-time supply
    Is the 'coating' you mention ARC for 405? - I always guess that the diodes in these were red. Never tried to make one lase..

    I will be back (to bump)
    BEYOND-FB3/APC40Mamba Black(clone & currently on loan) 2X 5paghetti & 2 I-Show 2X KGB 1000mW 532 DT40K (pair)XFX 1300 RGB full color RGB 30K DIY 3.5WRGB work in progress et al..assorted ttl chi-jectors--LOTS of LUMIA DIY pjs-
    Powered by Pangolin
    Former (2.5 yrs) ILDA Member- :-(
    uncertified ILDA LSO -- dont ask

  5. #5
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    Default lens making

    To obtain such a lens more than likely it would have to be custom made (expensive). Lens grinding is not that difficult, Look up in youtube for DIY's on telescope primary mirror grinding and as well as optics, to figure out the grind needed Ray tracing works well, also on youtube.
    If you can find a stone cutter (precious and semiprecious gems) they have the equipment to cut and polish stones "glass" at any angle or radius of any size. The difference between a stone cutter and lens lab is high dollars$.
    Just have your math right and go to the stone cutter.

  6. #6
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    Default

    ... you can try with an old laserprinter-f-theta, if or how strong it will block the 405nm -- with some luck the lenses aren't AR-coated ... have two old heads - one (older) with glass lenses, the other with lenses made from plastic/polymer ... none seems to have been coated ...

    Viktor
    Aufruf zum Projekt "Müll-freie Meere" - https://reprap.org/forum/list.php?426
    Call for the project "garbage-free seas" - https://reprap.org/forum/list.php?425

  7. #7
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    Default

    Quote Originally Posted by hakzaw1 View Post
    -- I made a double threads once..by error but-- its one of those unwritten 'rules'.. like two posts in a row.
    no big deal-
    Glad to see this thread- I want to know more about the stuff I have harvested from dozens of printers and other places.
    I have gotten one mirror array to spin- it makes a very nice flat beam- good for liquid sky. but not much beyond that..too little time for too many projects tick tock)
    got tons of FSMirrors.. a life-time supply
    Is the 'coating' you mention ARC for 405? - I always guess that the diodes in these were red. Never tried to make one lase..

    I will be back (to bump)
    The coating on the laser printer's "f-theta" lens are not meant for 405nm, they are possibly coated (i'm not even sure if they are coated) with infrared wavelength.

    I just spoke with an advance company that can make these custom f-theta lens to my needs for 405nm laser, but I need to order at least 1,000 pieces.
    I really do not mind to order 1,000 f-theta lens because I'm sure many people would find use for such lens.
    But more importantly I'm sure many people would buy a "PCB laser direct imaging printer" which is extremely affordable and can get PCB etches with traces/clearances around 0.07mm accurately all day. (For people/engineers that designs PCB which has FPGA PBGA with pins by the hundreds if not thousands.)

    It's just so sad that I still see people using the "toner transfer" method, they end up spending plenty of money, time and hassle for all the wasted ink and effort. I first saw toner transfer method 20 years ago... The method is still unreliable for for precision PCB traces.

    405nm lasers are also used for many different applications such as 3D printing. Polygon scanners can give 10x times better resolution than the current galvo laser direct imaging technology.
    Last edited by rajhlinux; 12-28-2020 at 03:38.

  8. #8
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    Default

    Quote Originally Posted by Lasertize View Post
    To obtain such a lens more than likely it would have to be custom made (expensive). Lens grinding is not that difficult, Look up in youtube for DIY's on telescope primary mirror grinding and as well as optics, to figure out the grind needed Ray tracing works well, also on youtube.
    If you can find a stone cutter (precious and semiprecious gems) they have the equipment to cut and polish stones "glass" at any angle or radius of any size. The difference between a stone cutter and lens lab is high dollars$.
    Just have your math right and go to the stone cutter.
    Well thank you for the helpful info. I will certainty look into homemade lens, I have few books about grinding and polishing custom lens.

    But I first must know how to make such lens that are "f-theta" type. How to make f-theta lens that are small rectangular shape like the ones in laser printer.

  9. #9
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    Default

    Quote Originally Posted by VDX View Post
    ... you can try with an old laserprinter-f-theta, if or how strong it will block the 405nm -- with some luck the lenses aren't AR-coated ... have two old heads - one (older) with glass lenses, the other with lenses made from plastic/polymer ... none seems to have been coated ...

    Viktor
    Thank you for your reply. Yes after weeks of research of such extremely limited info and companies that makes these special f-theta lens for laser printer, I found out that the modern laser printers now a days uses a plastic/polymer aspherical shaped f-theta lens. Oddly enough, some laser printers utilizes only one lens to give the f-theta effect rather than using 2 or 3 lens.

    Do you think it is possible to remove the AR coating using a special solvent for the glass lens type?
    Is the AR coating directly injected into the polymer material while it was manufactured?

  10. #10
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    Lightbulb AR coating

    as far as I know all coatings on lens are that a coating.
    on glass lens you can heat them in a frying pan slowly to were the glues melt making lens separation easy including coatings can be wiped off.
    all lens bend light to pre determined point dependent of the wave length of light passing through the lens.
    Example;
    532nm "Green" will focus at a different point than a 445nm "Blue" or 405nm Ultra violet, infrared, all wave lengths of light will focus to different point from the lens it' passing through. AR coatings are for anti glare or reflection, 91% Isopropyl and water may remove the AR coating after a over night soak and a baking soda rub out.
    10% by volume to water is a good strong soaking solution .
    this how coatings are done, JUST FYI. (87) How They're Made (Lenses and Coatings): Inside The Optical Lab - YouTube

    so removing a coating may not be your problem, the lens grind or shape might be your issue, From what I see in the pics you have provided, maybe you could slice a section out of the proper lens (round to flat)

    RAY TRACE and do your math! there's nothing like the smell of burnt brain in the morning!
    good luck!
    Last edited by Lasertize; 12-28-2020 at 07:01.

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