The Aperture Grille

Same idea as the shadow mask, metal rearranged. Unchanged: three beams, geometric colour selection, photographic screen, convergence, degauss. Changed: the openings are vertical SLOTS, not round holes, so the phosphor is vertical stripes and the beam is free to land anywhere up the stripe. That vertical freedom is why the grille transmits ~a quarter to a third versus the mask's ~18 percent.

On a real Trinitron (no dismantling): show white, look through a 10x loupe — continuous R/G/B stripes, not dots. Then find one or two faint HORIZONTAL lines across a plain field: the shadows of the damper wires. The grille is a set of taut strings that vibrate from sound and knocks; the dampers pin them, like a piano damper. Every Trinitron has them — the cost of the brightness.