There is a junction which I pass quite often and has always puzzled me. 

Basically there are traffic lights which allow traffic to flow in both directions on the major road, and then stop said traffic to allow vehicles to merge from the minor roads. 

Question is, if I was going in the direction the camera is pointing, it would be hard for me to turn right (whilst green) as the oncoming traffic is always busy and there are no breaks.  When the lights turn red however, it would be easy to turn right as long as it was safe to do so, as oncoming vehicles are stopped.

Is that correct though, or should I wait until it is safe to turn whilst the lights are green (thereby blocking traffic behind me from going straight and irritating everybody)?

The lights apply to the line after the junction.

Highway code rule 174-

You MUST NOT enter the box until your exit road or lane is clear.

However, you may enter the box and wait when you want to turn right, and are only stopped from doing so by oncoming traffic, or by other vehicles waiting to turn right.

At signalled roundabouts you MUST NOT enter the box unless you can cross over it completely without stopping.

White zig zags lines are there due to the dropped kerbs indicating a designated crossing point not covered by pelican or zebra crossings.

They should not be crossed if a pedestrian is starting to cross the road there.

That makes complete sense!  The position of the traffic lights clears it up, because although for all intents and purposes (due to the box junction) if they are red you have to stop before the junction, when it comes to turning right and doing so whilst they are red, they don't apply. 

I think I knew the answer, but needed the reasoning explained for it to "click"!