What does a lens do in a projector?

In a projector, the lens plays a crucial role in determining how the image is displayed on the projection surface. Specifically, it focuses and enlarges the image produced by the projector's light source and imaging chip. By bending light rays, the lens ensures that the image from the light source is projected clearly and at the appropriate size onto the screen. This focusing capability is essential for achieving sharp and detailed images, which is why the lens must be carefully designed and well-matched to the projector's optical system.

The other options do not accurately describe the function of a lens in a projector. Altering sound quality pertains to audio components rather than optical elements. Converting a signal from digital to analog is a function related to processing the input signal, not the projection process itself. Stabilizing an image during projection can involve other mechanisms, such as digital processing or special features within the projector but is not a primary function of the lens. Hence, the primary responsibility of the lens is indeed to focus and enlarge the image, making it essential for effective projection.