DLP660TE: Use in a 3D Printer design

Hello, Robin.  There are multiple questions and devices listed in your post.  I will attempt to address each one.

First, let me start by confirming your intentions are to create a 3D printer using either the DLP660TE with visible light or the DLP9500UV with ultra-violet light.  This is important because using the device within the datasheet's specified operating conditions will help ensure longest life for the device.  As you noted the DLP660TE's specifications are written and validated with respect to video projection applications.  The DLP9500UV on the other hand has specifications written and tested for industrial light applications.  However, when it comes to duty cycle concerns, all DMDs regardless of application or wavelength will benefit from having a near 50/50 duty cycle.  Since print speed is not a key concern for you, then you could consider exercising the pixels with the illumination off during printing breaks to maximize device lifetime.  You may want to read this app note which describes many system design considerations relevant to 3D printing.

You've mentioned being flexible in your print speed and light wavelength requirements for your 3D print application.  Other considerations are illumination power and pixel-level control.  

Regarding illumination power, both devices have a section on thermal information in the datasheet including dimensions of the thermal pad on the backside of the package.  You will want to be sure you are within the DMD operating conditions and can keep the device adequately cooled per the datasheet guidelines at the power levels you want to use.  

Regarding pixel-level control, the DLP660TE's controller is designed for video applications, and so it will have built-in data processing algorithms that optimize your digital data for the best video experience.  For some 3D print applications, potential print artifacts from the video processing are not acceptable. Ultimately, it will impact the smallest feature size you can print.  On the other hand, with a device like the DLP9500UV, you have an FPGA-based controller with advanced pixel-level control capabilities, higher bit depth for grayscale patterns, and faster update rates.

In summary, if you intend to 3D print with visible light within illumination power levels that can be adequately cooled, the DLP660TE may be a good fit. If you haven't already seen it, Keynote Photonics offers an evaluation module for this chipset: http://www.keynotephotonics.com/lc-4k-uhd-hld/

 As your performance requirements increase, there are several Advanced Light Control chips to consider.  We have High Speed Visible devices warranted down to 400 nm, for example, that are popular for 3D printing.  And of course we have the devices with the UV coated windows that support down to 363 nm.  Check out http://www.ti.com/lsds/ti/dlp/advanced-light-control/advanced-light-control-applications-featured-applications.page#3D-Printing for a full range of industrial chip offerings compared by key 3D print specs.

Thanks for the reply Raecine.  Yes, we're looking to develop a 3D Printer based on the DLP660TE (using visible light).

Thanks for mentioning the idea of exercising the mirrors in-between print layers with the illumination turned off - I'd already considered doing this as a way of getting round this issue.  Good to know it's a recognised method!

For us control of bit depth for grayscale patterns isn't a requirement - we either want to cure a 'pixel' of resin, or not cure it.  Either 0 or 100% grayscale is fine for us.  Update rates are also not important, as these are unlikely to be a bottleneck for our 3D printer.

Is there a document that outlines the video processing that goes on within the FPGA/DLP controller?  I haven't come across anything in the datasheets.  Edge blending is mentioned in your document titled "Using TI DLP® technology to make digital signage more effective" , but it seems to suggest that this would be carried out in separate image processing software?

Thanks!

Robin