Inside the Tube: A Look at Video Monitor Technology (page 3)

In-line Configuration

In 1969, Sony introduced the first in-line configuration CRT called Trinitron. It uses a single electron gun with three cathodes to produce three electron beams in line with each other on the same horizontal plane. It also uses vertical slits stripes instead of phosphor dots, and a screen of vertical slits called an aperture grille. The in-line electron beams and vertical phosphor stripes improve horizontal resolution. The vertical aperture grille allows the Trinitron CRT faceplate to have a vertically flat surface instead of spherical like a Delta CRT of other in-line CRTs. The "flatscreen" reduces image distortion at the corners of the screen, and reflects ambient light away from the viewer. But to scan the vertically flat faceplate properly, the electron gun must be further from the faceplate. so Trinitron CRTs are generally longer and heavier than Delta CRTs.

In 1972, RCA introduced an in-line CRT similar to Sony's. It uses three separate in-line electron guns and an aperture mask with vertical slits. As in the Trinitron, the in-line electron beams and the vertical phosphor stripes yield better horizontal resolution than the Delta CRT. The vertically slotted aperture mask allows the CRT faceplate to be vertically flatter than a Delta CRT, but not as flat as a Trinitron CRT. The length and weight of the RCA in-line CRT is also intermediate between a Delta and a Trinitron CRT.

Of course, all three types of color CRTs have continually undergone refinements since their introductions, but it is probably safe to say that a color monitor with an in-line CRT is superior to one with a Delta …