“you can just put an LCD screen with the same resolution on the outside of the glasses, and use it to block real-world pixels however you like.” That’s a clever idea, but it doesn’t work. [..] a pixel at that distance would show up as a translucent blob several degrees across
The LCD solution was the first one that came to my mind too, and I'm surely missing something here but why wouldn't the regular translucent pixels suffer from the same problem as that above?
Probably, which is why I think a better idea is to watch the person's eyes and try to guess their focus. That combined with a higher resolution screen (maybe 3x?) would let you try to mask a diffraction mask to match where light should be coming from for that part of the person's eye.
At least I think this should work, combined with being able to control the translucency of the pixels would allow it to be fairly accurate.
The additive pixels are taking a separate optical path, combined in at the last second by either a beamsplitter or a waveguide.
In current commercial HMDs, the additive pixels are statically lensed to a fixed focus distance (not infinity, as a sibling comment asks, but rather a best guess of where the user will be focusing most often, e.g. 1.25 meters).
Using dynamic lenses to put the additive pixels at any focus distance is an exciting topic of current research:
Dynamic lenses could also be put on the forward-facing / physical-reality optical path both before and after the subtractive pixel layer, to put the subtractive pixels at any distance as well, solving the problem. (This would incidentally also allow lensing physical reality itself to any distance too, creating perfect / hyper-real vision correction.)
Comments
“you can just put an LCD screen with the same resolution on the outside of the glasses, and use it to block real-world pixels however you like.” That’s a clever idea, but it doesn’t work. [..] a pixel at that distance would show up as a translucent blob several degrees across
The LCD solution was the first one that came to my mind too, and I'm surely missing something here but why wouldn't the regular translucent pixels suffer from the same problem as that above?
Probably, which is why I think a better idea is to watch the person's eyes and try to guess their focus. That combined with a higher resolution screen (maybe 3x?) would let you try to mask a diffraction mask to match where light should be coming from for that part of the person's eye.
At least I think this should work, combined with being able to control the translucency of the pixels would allow it to be fairly accurate.
The additive pixels are taking a separate optical path, combined in at the last second by either a beamsplitter or a waveguide.
In current commercial HMDs, the additive pixels are statically lensed to a fixed focus distance (not infinity, as a sibling comment asks, but rather a best guess of where the user will be focusing most often, e.g. 1.25 meters).
Using dynamic lenses to put the additive pixels at any focus distance is an exciting topic of current research:
http://www.quora.com/Volumetric-3D
Dynamic lenses could also be put on the forward-facing / physical-reality optical path both before and after the subtractive pixel layer, to put the subtractive pixels at any distance as well, solving the problem. (This would incidentally also allow lensing physical reality itself to any distance too, creating perfect / hyper-real vision correction.)
I'd guess the display pixels are holographically projected into the field of vision at infinity?