A TV picture tube (CRT) that had a flatter viewing surface than the traditional rounder tube. Up to 30% more glass was used to make the screen flatter. Also known as a "flat screen," "flat face CRT" or "flat square tube" (FST), the flat CRT provided less distortion at the edges and was the preferred design.
Flat and Thin
Flat CRTs were considerably thinner than earlier CRTs, although still not as thin as flat panel displays. See flat panel display
and flat panel TV
A Flat and Thin CRT
This is the picture tube of Samsung's flat and thin TV (viewed from the top). Introduced in 2005, it was considerably thinner than earlier CRT TVs, enabling a 32" TV set to be only 15" deep. All CRTs, flat or round, gave way to the much flatter LCD and plasma panels.