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DLPC3478: 1bit图片在internal patterns显示模式下,高帧率投影过程中颜色切换有时候会出现问题

Part Number: DLPC3478
Other Parts Discussed in Thread: DLPA2005,

DLPC3478+DLPA2005+DMD3010

我们使用的是Internal patterns模式,有两个pattern set,其中set1包含12张1bit图片,set2包含1张1bit图片;

投影顺序为①以B光投影set1的12张图片,然后②以R光投影set2的1张图片,再③以G光投影set2的1张图片,最后④以B光投影set2的1张图片;

问题现象:投影帧率在1250hz上下,②原本应该投影R光的,非常容易没有投R光,而是B光

当设置前后沿为0.154ms,曝光为0.46ms时(投影帧率1300),非常容易出现上述问题;设置前后沿0.2ms,曝光0.4ms时(投影帧率1250),也会出现这个问题,但是出现频率会低一些;

想请问R光没有切换过来的原因是什么?以及有没有比较好的方式避免该问题?

best regards

  • 使用什么软件版本?

    投影顺序为①以B光投影set1的12张图片,然后②以R光投影set2的1张图片

    有没有问题?

    确认没有超出规格曝光时间设置。1250HZ对应配置曝光时间多少?

    Internal Pattern Mode Timings:

    Pattern Type
    Sequence Index
    Exposure Time Range (us)
    Sequence Min Pre-Exposure Dark Time (us)
    Sequence Min Post-Exposure Dark Time (us)
    1-bit Monochrome
    18
    200 - 399
    171
    31
    17
    400 - 799
    171
    31
    16
    800 - 799
    171
    31
    15
    1800 - 3799
    171
    31
    14
    3800 - 7600
    171
    31
    1-bit RGB
    25
    600 - 1799
    171
    31
    24
    1800 - 3799
    171
    31
    23
    3800 - 7600
    171
    31
    8-bit Monochrome
    20
    3464 - 6928
    171
    31
    21*
    1677 - 3463
    171
    31
    8-bit RGB
    22
    10912 - 21824
    171
    31

     

    *Sequence 21 is a special sequence that displays 7-bit patterns. The least significant bit of the 8-bit pattern data will be ignored.

    Notes:

    • For internal patterns, there will be an additional variable delay of ~3000 us at the beginning of every pattern set.
    • Exposure times shorter than the above values are not possible. Longer exposure times will operate with decreased timing accuracy and behavior is not guaranteed.
    • Shorter dark times are not possible. Longer dark times can be used. The maximum possible dark times for a desired exposure time are:
      • Tmax pre-exposure dark time  = ( 27306us + tsequence min pre-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)
      • Tmax post-exposure dark time = ( 27306us + tsequence min post-exposure dark time ) * (Tdesired exposure / tsequence minimum exposure)
  • 感谢回复!

    投影顺序为①以B光投影set1的12张图片,然后②以R光投影set2的1张图片;在2上也会出错;

    我们曝光前沿0.2ms,曝光时间0.4,曝光后沿0.2ms,每张图都是1bit单色(1 bit monochrome)(不同图片的颜色切换应该不算是RGB吧?)

    曝光参数通过98h的指令写入;

    图片序列设置98h指令执行一次,之后是不断以9Eh的指令去触发run once,偶发出现颜色切换异常

    best regards

  • 你用TI GUI lightcrafter测试。再抓下I2C命令对比。

    https://www.ti.com/lit/pdf/DLPU112

    ...