What does the depth of a rear-projection TV set depend on?

The depth of a rear-projection TV set is primarily influenced by the size of the screen. Larger screens generally require more space to house the necessary components, such as the projection system and the optics used to create the image on the screen. As the screen size increases, the physical dimensions of the rear-projection unit must also increase to accommodate the larger image and ensure proper viewing distances.

While other factors like technology, resolution, and brightness can affect the overall performance and quality of a rear-projection TV, they do not directly dictate the physical depth of the unit itself. The size of the screen is the most direct factor in determining how deep the television must be in order to deliver an appropriate viewing experience.