We know that Rimmer is described as a "hard light" hologram, but is there an apparatus that physically projects his image, or is there something inside of him that causes the a hard light field so-to-speak.
It's a "light bee" that generates Rimmer, essentially it floats "inside" him.
Here is it floating (source Red Dwarf Props):
Here's Lister holding it (source wikipedia):
Originally it was soft light, but it was upgraded by Legion in the episode "Legion" (Series 6, Episode ")
Here is Legion holding it during the upgrade (source Red Dwarf Props):
And a close up of the prop (source Red Dwarf Props):