Livroscopes hold a book or an e-reader above the reader's head, text downwards, to read lying on one's back.
The weight of the book is compensated by elastic bungees. This design is inspired from architect's lamps whose weight is compensated by springs.
The weight of the book is compensated by a counterweight.
The weight of the book is not compensated but it does not fall down because the arm is short.
This livroscope stands on the floor on each side of the bed. A double-bed version with two book holders is feasible.