Motorized Wheel Chair Source

I'm looking for a laptop mount for a wheelchair that will not interfere with my full size plastic tray I use.

I have a full size plastic tray that I use for eating, writing, drawing, ect. but I also use a laptop a lot. I would like to find a wheelchair laptop mount that will swing away when I do need to use my tray, or for transfers that I can use will still keeping my tray on. The reason I would like a mount for my laptop is because I have tilt on my power chair so I would like to be able to tilt will on my laptop without having my laptop slide toward me but would like to also have one that won't interfere with my tray so that I won't have to have someone continually remove my tray when I want to use my laptop or put it back on when not using my laptop. I've looked and seen some that look interesting but none of them out-wordly say they won't interfere with a tray.

thanks

Patben