An Aperture Grille instead of a Shadow Mask. Other picture tubes require a Shadow Mask that divides the screen into tiny dots or slots of color. The Trinitron CRT replaces the Shadow Mask with Sony's exclusive Aperture Grille. It takes the form of vertical slits that continue unbroken from the top of the screen to the bottom. Horizontal cross-bars are eliminated.
More electrons reach the screen.
The Shadow Mask prevents some electrons from reaching the screen. A screen that's vertically flat, not vertically curved. Only the Sony Trinitron CRT has a cylindrical screen that's vertically flat, from top to bottom. So straight vertical lines actually appear straight. And ceiling lights are reflected down to the floor - not back into your eyes where reflections would wash the picture out.