You may have seen a story that Amazon was just awarded a patent for photographing objects against a white background. Don't worry, you're not all about to get sued - the patent is actually for their very specific photo setup, that they use for very high throughput to photograph things for their online catalog (their studio takes 19,000 images a day!!!!). To infringe the patent you would have to use a specific camera lens with specific settings and object, photo, lights, etc, at all fairly specific distances and angles, and so no one would be using the same setup in their LEGO room. Add to that the fact that it is pretty much impossible to distinguish one photo of an object with a white background from another, this patent would surely never get enforced, and if so, the patent would surely fail the obviousness test under 35 USC 103.*
That said, you can read the patent and get some ideas of setting up your own, much smaller, photo studio. The key seems to be the multiplicity of light sources - one aimed at the object (from above and behind the photographer), and four aimed at the white backdrop. Anyway, here are the important figures from the patent, and also a picture of Amazon's high-throughput photo studio. I think it would be interesting to try a much smaller scale variation for a home LEGO photo setup.
*As they always say at the start of the Supreme Podcast - "This (post) does not constitute legal advice. If you need legal advice, please consult Athos."