Inverting pressure plate without powering piston

Question

I'm working on a trap, where if a person steps on a pressure plate, then the pistons deactivate and a pit forms in front of the plate. I decided to do this like a vertical jeb's door (a piston door in a flat surface.)

The issue I am having is that the pressure plate is powering the upwards piston directly next to it. Is there a way to invert the charge from the presureplate without powering the piston? Preferably without moving the plate away from the pistons.

Side view 1 shows how I implemented the jeb's door. The issue is that the pressureplate that triggers the trap is also activating the [s^] piston directly next to the plate. I hope my diagrams are understandable, otherwise I can provide screenshots. :3

• [p] = pressureplate
• [d] = dirt
• [s] = stickypiston (>,<,^,v = Piston Direction extended)
• [r] = redstone
• [1-4] = repeater with 1-4 number of ticks
• [a] = air
• |[b]| = Section for Side view
• [t] = redstoneTorch

Top view

[p][d][d][d][p]

Side view 1 (|[b]| for side view 2)

[d][d][d][d]|[d]|[d]
[r][1][s][>]|[^]|[r]
[d][d][s][>]|[s]|[d]
[d][d][d][d]|[d]|[t]

Side view 2 (|[b]| for side view 1)

[p][a]|[a]|[a]
[d][d]|[d]|[d]
[r][^]|[^]|[^]
[d][s]|[s]|[s]

Answer 1

I am not sure if I understood correctly, but you can use a sticky piston under the pressure plate to cut off a wire that powers the other three pistons:

And with the pressure plate 'on':

You can power the side pistons with repeaters, if you want the ground to be flat.

Answer 2

You cannot invert a pressure plate, but you can move the piston away from the plate.

I don't quite understand your diagram, but from your description of what you're trying to do I've come up with a solution.

I hope you can see all the wiring in this picture, the other side is an exact mirror of this one, the repeaters are set to two ticks and all the pistons are sticky.