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pattern confusion in LightCrafter 4500

Dear All

I encountered a pattern confusion problem when I set the LightCrafter 4500 working in external trigger mode  with more than 24-bit binary pattern involving. The trigger signal is outputted from a high-speed vision platform to synchronized these two device (1000 fps). If less than 24-bit binary patterns are used, this system can work properly.  However, when more than 24-bit patterns are used, the system can work well firstly, but the pattern sequence will be changed after a while. Because the high-speed vision platform works in a normal mode, it just capture the image and output trigger signal. I guess the projector maybe have some problem in setting or other things. Is there someone encounter this problem too?


  • Hello Jun,

    Are you using internal patterns stored on flash or external streaming patterns? I suspect that the issue you see when using more that 24-bit binary patterns is a result of the image load time. You shouldn't see a problem though is using less than 48 binary patterns from only two images stored in flash.

    Best regards,


  • Hello Blair

    The pattern is stored on flash. according the description in TI official document, this problem shouldn't happen. However, we indeed encounter this problem. Do you have some idea to solve this problem or some suggestion to confirm its real reason?

    Thank you for your help.


  • Hello Chen,

    In order to get a better understanding of the issue, please provide the following information:

    1. Pattern Sequence Internal Trigger and Pattern Exposure times
    2. Pattern Sequence
      1. For every pattern provide its bitdepth and flash index
    3. Image load times
      1. For each flash image used in your sequence, please use the "Get Load Image Timing" tool and tell me the load times for each image

    After I can look at your setting I should be able to help better!

    Best regards,


  • Hi Blair

    The DLP 4500 works in external trigger mode with two 24-bit color image stored in flash. The mainly settings are listed as follows: 

    Figure 1   Main setting

    Figure 2 image lode image of pattern 1 (index 28)

    Figure 3 image lode image of pattern 2 (index 29)

    Figure 4 images of pattern 1 (1 bit)

    Figure 5  images of pattern 2 (1 bit)

    I wonder if there is any limitation for the width of external trigger signal ? another information I can offer is that this problem is not always appear. It can work well sometimes.

    Best Wishes



  • Hello Chen,

    Once the configuration is done from the GUI you can close the GUI and try it.

    We have got similar observation from other customers. Why we need to close the GUI is discussed in here