DLPC350: Pausing Pattern without turning off LED in Pattern Sequence Mode

Dear Vivek,

Thank you for your reply. I have some follow questions regarding your reply.

Issue 1.

I notice that there is a 'clear DMD after exposure' checkbox in the GUI. Is this checkbox relevant to the DMD reset you mentioned? When this one is unchecked (Don't clear DMD after exposure), the pattern will still goes off upon pausing. Does that mean this option is only applicable for continuous display of pattern sequence? 

Meanwhile, by 'sending the last pattern repeatedly', is this achievable with the use of pattern sequence LUT? So far I can only define a LUT, and display patterns according to the order of sequence. However, I didn't find anywhere on the programmer guide to display a specific pattern from a pre-defined LUT. Is there a section I can refer to on the programmer guide?

I think of redefining the LUT for each single pattern, setting the pattern to repeat itself, and validating the pattern sequence each time. But this doesn't sound like a good move because validating the sequence is slow and it needs to switch off the system for validation. What it leaves behind is very unpleasant flash (LED on and off) when a new pattern is defined and displayed.

Issue 2

Yes, this issue is relevant to issue 1. If I can ask the projector to display a particular pattern from LUT, or redefine the LUT for each single pattern, then this will no longer be a problem. I prefer using the former solution but I cannot find relevant section from the programmer guide that describes how this can be achieved. In addition, I think the action 'jumping to the next pattern' should be relevant to the use of triggers. From the programmer guide, there are four trigger controls: Trigger Out1, Trigger Out2, Trigger In1 and Trigger In2. It seems that these four controls define only the triggering mode (rising/falling edge), but not defining the trigger itself. And they requires validation of pattern sequence whenever they are called. It there anyway for me to directly define the triggers 1/0 status?

If the latter solution is the only solution, then this thread should be solved. 

Thank you and looking forward to your reply!

Best regards,

Jeff Leung

Dear Vivek,

Thanks for your reply. I have tested your solution using DLPLCR4500 GUI 3.1.0, and my firmware version is 3.0.0.

When testing, I observe that when pattern sequence are paused, LEDs are indeed switched off. Then I change the LED setting to manual, the LED goes on (before I see no light through the lens but now there is blue light), but no pattern is displayed. If the LED is on, it seems like the DMD is not in position. I have tried checking and unchecking the "clear DMD after exposure", both did not show any pattern.

Below are the setting in GUI:
1. Pattern Sequence Mode, Pattern Source from Flash, Internal /External Trigger
2. Individual Pattern Setting: Blue Light, Internal Trigger
3. Bit plane selection: Flash index = 0, bit-depth = 1
4. Clear DMD after exposure (both checked and unchecked cases are tested)
5. Pattern Sequence: R0 R1 R2, repeat mode

Initially LED Driver Control is set to automatic. Once pattern is paused, I switch it to mannual with Blue LED on. I can obviously see the LED goes on, but no pattern is displayed. I am now considering using the external output from DLP to send a signal back to computer, and further control the camera for image acquisition. In that case I don't need to pause and hold still the pattern in between. I will let you know if it works.

Thanks,
Jeff