DLP4500: Missalignment with "poster-mode"

Sebastian Burck

Part Number: DLP4500

Hello,

I try to use the DLP 4500 to exposure photoresist of PCBs. I use the PRO4500 from Wintech with a UV LED light source and a 92mm optic. Actually I split my images to a size of 1280x800 px and put them via HDMI to the DLP4500 who projects the image to the pcb for a amount of time. I attached the DLP4500 to a CNC machine to move accurate. After the first image is developed I move the projector to the next area and also project the next image. I attached a scan of a PCB Testpattern where you can see my missalignment.

Till now I tried the following:

- Cropp the outer areas to remove disortion effects
- Let the images overlap to have no "borders"
- Move the image and the CNC continously from one side to another (this result in a blur effect)

Do I have problem with my projector alignment on the CNC? Are there any calibration routines or ideas? Or is the problem the scaled resolution of 1200x800px and I need to use the pattern mode?

Any ideas are welcome - many thanks

Sebastian

over 5 years ago

0 Sanjeev over 5 years ago

TI__Mastermind 30875 points

Hi Sebastian,

In the picture above the misalignment it appear to me problem with the projector alignment on the CNC. Is it appearing exactly at the position after you move the projector head?

Regards,

Sanjeev

0 Sebastian Burck over 5 years ago in reply to Sanjeev

Prodigy 20 points

Hi Sanjeev,

I'm sorry - but is difficult to say. The picture in real-world-coordinates is 65.6mm x 41mm and ist difficult to measure. I can only make those test pcbs to see results - but can you explain a bit more to me what you mean with "Is it appearing exactly at the position after you move the projector head?" I can say the following - the picture is exactly 65.6mm width and I also move the CNC 65.6mm. The X, Y, and Z axis of the machine are perfectly align - but I'm not 100% sure that the projector is 100% align on the CNC. But If you also have the opionion that the missalignment of the projector in relation to the surface will cause this problems I will try to make a mounting that I can align (not sure how to measure). Thanks for your reply.

Regards,

Sebastian