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DLP4500NIR: Pixel flight path as a function of time, or control of dithering frequency

Part Number: DLP4500NIR
Other Parts Discussed in Thread: DLP4500

Hi there,

I'm hoping to get more information on the motion of the individual micro-mirrors in the DLP4500 as they transition from the on-state to the off-state. I have been considering controlling the device such that it accomplishes not image formation, but translation of a laser very rapidly. For example, if I were to display binary data across the entire display, from 0 to 1, and back, at the 4kHz spec, would it be possible to plot, as a function of time, the angular rotation of the micro-mirrors?

Along the same lines, if I were to display a constant 128 value across the entire DMD (50% DC), forcing the display to dither, is it possible to plot those trajectories as a function of time? Also, is it possible to control the frequency at which the DMD dithers the mirrors in order to create the grayscale value? These pieces of information would be incredibly helpful for a project I'm working on in the lab. Please reach out directly (personal message?) or on this thread with more info. I haven't been able to get an idea exactly how these mirrors move from the on to off state. 

Thanks,

Blake 

  • Hello Blake,

    Could you elaborate a bit more on your experiment? In general we don't go into the details of the actual angular mirror switching time. The DMD is intended to be operated as a digital device only taking into account the on and off state. You can however achieve various duty cycles (such as 50% 80% etc).

    Thanks,

    Kyle

  • Hi Kyle,

    I understand the intent behind the digital operation of the DMD. My application which I've been considering, is based on leveraging the motion of the micromirrors during their transition from the off to on state. My goal would be unorthodox, to somehow sweep a laser (reflected off of the DMD) in 1D and take advantage of the transition from the off state to the on state, to do so. My question then, is to understand the motion of the micromirrors, as they transition to different states, and the linearity of their motion between those states. It's a bit of a weird question, seeing as I'm uninterested in displaying images, simply taking advantage of the moving elements.

    What is the underlying PWM frequency driving of the duty cycle? 

    Thanks,

    Blake

  • Hi Blake, 

    Kindly allow us some time to look at your query and we will get back to you as soon as possible!

    Thanks & Regards,

    Hirak.

  • Hi Hirak,

    Thanks for the help!

    If there are more specifics I can offer from the application side, I'm happy to do that- just let me know; I'll do my best.

    Respectfully,

    Blake 

  • Hi Blake,

    Thank you for your patience. The mirror transition speed is very fast compared to the pattern rate (4K Hz). The typical flight time for the mirror form one sate to another is 1-2 Microsecond and followed by 4-5 microsecond settling time. 

    The 4KHz  rate is for 1-bit binary pattern. The mirror are either in ON or OFF state, there is gray value. Moreover in a period 250 Microsecond , the flight time for mirror is  1-2 microsecond. 

    Does this meet your application requirement?

    regards,

    Vivek