Flashing white line when displaying an image

[JCook 57]

Does anyone know why I get a horizontal white line flash when I display an image, say a colored circle on a black background. When I put it in a loop, the line seems to scroll vertically either up or down. Increasing the refresh rate of the monitor makes the line wider and scroll at a different rate.

Do you have any thoughts as to how I could nullify this effect or where it comes from?

I have attached an example vi.

[altenbach]

Right-click on the picture indicator. Under "Advanced..", make sure "smooth updates" is checked. That should cure it. good luck!

[JCook 57]

Thank you for the advice. However, it seems I already had that option checked, and I get the same results when the option is deselected. Strange. Do you have any other thoughts?

[altenbach]

Hmmm, interesting. What version of LAbVIEW are you using?

If I open your VI in 7.1, the option "smooth updates" is deselected and if I select it, the flickering goes away.
The flickering also goes away if I deselect "erase first".

So, try the following:
"erase first": NOT checked.
"Smooth updates: Checked.

Also try to see if there is an updated driver for your video card.

[JCook 57]

Aha! The 'erase first' thing fixed it. Thank you so much for the help.