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DMD chip with diamond-shape pixels

We recently purchased a LED projector from Vivitek for structured light application. The model is Qumi and its native resolution is 1280x800. However, we didn't get to know until we turned on this projector that this DMD chip has diamond-shape pixels instead of square-shape. After talking to the sales people, the only thing she knows is that the DMD size is 0.65". The diamond-shape pixel design won't work for our structured light application. We have to purchase another projector with regular square-shape pixels. However, the shape of the pixel is usually not specified in the disclosed document. And I couldn't find any data sheet for the 0.65" DMD chip on TI website either. For our application, we would need a LED projector with regular square-shape pxiels at relative large resolution (>=1024x768). My questions are:

1. What is the design trend of the DMD chip in terms of pixel shape? 

2. Do you have square-shape pixel version available for 1280x800 or higher resolution?

3. How do we know if the projector has diamond-shape pixels or square-shape pxiels when we make a purchase?

I would greatly appreciate your help on this new issue for us.

  • Jiahui,

    I am from the DLP Embedded group, and the DMD which you mention is not available as a catalog part. I am not familiar with it. You were told that it is a diamond array? Or did you discover it by examining it?

    Do you have plans to develop your application using a DLP chipset? Or is your approach to only use an off-the-shelf projector?

    I can't speak definitively to the question about  the trends in "square" array vs "diamond" array DMDs. TI DLP makes both kinds.

    I also am not surprised that vendors of projectors don't make it clear which geometry their projectors use. To most people it wouldn't matter.

    Best regards,

    Pascal

  • Hi, Pascal,

    Thank you very much for your reply. It is very hard to find a person who is aware of  this diamond shape pixel nowadays. Nobody told us about it during purchase. When we started to do measurement, we got some unusual results. Therefore, we project some dots and lines onto a white wall and found out the pixels are actually rotated 45 degrees from its normal position. I also found a forum discussing about this topic. It has some nice pictures to show you what I am talking about. http://test.avsforum.com/avs-vb/showthread.php?p=20847203

    We would like to develop our application using an off-the-shelf projector at this point. Do you know what series (size, resolution, etc.) of DMD chipsets will have the diamond shape? Is there any disclosed information from Ti website we can review? I hope Ti would not totally replace the square shape with the diamond shape. Thanks!

     

    Jiahui