Here's another thing worth pointing out: you may think that because they will use ordinary LCDs that there should be some extra plate or something over the screen to produce the holograms -- why don't ordinary LCD screens produce holograms?
Here's the answer: when the pixel size or aperture that light passes through is small enough relative to the wavelength, the light naturally diffracts. And if the light is coherent (laser) and monochromatic (which it usually isn't in casual use), the spreading waves through all the pixels will interfere in a predictable way, according to which pixels are turned on.
See this for a visual explanation:
There is an equation, called the diffraction equation, that relates pixel size, wavelength, and angular spread, that I won't bother to state. Suffice it to say that the current highest density LCD displays have pixel sizes right in the sweet spot to make Jepsen's idea work with near-infrared light.
This also means that if the pixel size could be shrunk even smaller, you should start to see diffraction patterns with visible light, and closer to the blue side of the spectrum. You could make holograms with an ordinary display, and no extra diffraction plate.
Actually, I think this poses a problem for display-makers -- but not hologram-makers! -- as it means if the pixel size drops below a certain "diffraction limit", the light starts to interact in undesirable ways.