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DLP6500FYE: DMD pattern not consistant

Part Number: DLP6500FYE

Hi team,


Good day.

Our customer is using the DLP6500 development kit and the reflected projection will change sometimes which makes the projection unstable. The pattern looks unchanged on the DMD from human eye. The customer tested it with a pure white pattern and a stripe pattern. The situation is when light is projected onto the DMD, the reflection will change sometimes.(randomly so it is not because the dark timing) The light source has been checked and it is stable. Attached is a video recorded, this is the reflection from the DMD. It is under pattern mode and the image uploaded is pure white and dark time set to 0 on Repeat mode. Do you have any suggestions as a workaround for this?

Your assistance on this is appreciated.


Regards,
Carlo

  • Hi Carlo,

    Can we get Firmware and GUI version customer is using.
    is the same issue repeated when projecting internal test patterns.

    Thanks,
    Shivakumar 

  • Hello Carlo,

    The video shows a very faint greenish blob near the center that is fluctuating.  Is that correct?  Can you describe in a little more detail the illumination and projection system.

    Would you be able to show the both the Pattern Design and Pattern Settings pages from the Pattern Mode Page.  Is this indeed Pattern on-the-Fly Mode?

    Since it doesn't appear changed to the human eye, What are they using to detect the change.  Be aware that there is an underlying refresh rate that will show up about every 105 us.

    Fizix

  • Hi Fizix,

    Good day.

    According to our customer, the internal pattern changes pretty quickly making it difficult to tell. The illumination system uses an expanded IR which is the reason they use a card to show the projection. The customer used pure white and one stripe pattern to test and photos are attached and they can tell the rapid change on the reflection.



    Regards,
    Carlo

  • Hello again Carlo,

    Thank you for the Design Page screen shot.

    In the second picture, what is the orientation of the DMD with respect to the card?  Is the long axis of the DMD vertical or horizontal?

    Also, what is being used to capture the picture?  I.e. Is the picture taken with a cell phone? 

    The scrolling shutter of a cell phone may capture artifacts that are not representative of what is actually happening, since a cell phone picture is not taken all at the same time.

    Fizix

  • Hello Fizix,

    The customer shared videos, however, the file reaches the limit size since it is about 150MB. Do you have cloud storage where I can upload the files?

    Regards,
    Carlo

  • Hello Fizix,

    Good day.

    According to our customer, the orientation of DMD, the long axis is vertical and the video is taken with a cellphone. Attached are the videos.



    Regards,
    Carlo

  • Carlo,

    Since there is no synchronization between the cell phone and the projection, I cannot tell if this is synchronization artifact or something else.  I am proceeding on the information that the pattern does not look changed to the human eye.

    It would be more helpful if a camera that can be triggered is set up to one of the output triggers from the system and recorded with synchronization.

    Can you also find out what version of the Firmware and GUI software they are running?

    Fizix

  • Hello Fizix,

    According to our customer, they are using the software of DLP Lightcrafter 6500&9000 version 4.0.1 and they have been using this before and it works fine.

    Is there any other workaround that we can suggest to the customer?

    Regards,
    Carlo

  • Carlo,

    If the customer is using SW 4.0.1, then they should be using FW 5.0.1.  The firmware version can be read in the GUI on the lefthand column.

    From what you are saying, this has worked previously.  What I am trying to discover is what has changed:

      • Are they using exactly the same project?
      • Are they using exactly the same SW version?  It sounds like from the response the answer to this is yes.
      • Are they using exactly the same FW version?  It sounds like from the response the answer to this is yes.
      • Are they using exactly the same Hardware?  I.e. the same kit and DMD or did the kit or DMD change?
      • Do they still have a working system that does not do this when observed with the cell phone?

    Please send a friend request.  I would like to get the actual project that they have gotten this from.  Since the DMD is reflective, the wavelength of light should not matter.

    Fizix