Top of the tubes – when Trinitron ruled the living room

By Valens Quinn

While the age of fat, bulky cathode ray tube (CRT) televisions is clearly over, all is not forgotten. With Sony’s illustrious Trinitron technology hitting its 40th birthday in 2008, the king of CRTs definitely deserves a few lines of mention here.

Born in 1968, Trinitron technology was Sony’s answer to the conventional CRTs used by the competition. Trinitrons became widely accepted the as premium technology, and were a good deal brighter, had better contrast ratios, more vibrant colours, and sharper pixel focus – but were also more expensive.

One of the keys to Trinitron’s superior image was a clever device called an aperture grille. This was placed between the electron gun and the screen, and masked the electrons shot to illuminate the screen’s phosphors coating. Conventional CRTs also used a masking device called a ‘shadow mask’, which consisted of a thin metal sheet perforated with thousands of tiny holes. In contrast, Sony’s aperture grille was made of thousands of tiny vertical wires, held in place by two horizontal restraining wires.

As the aperture grille was less dense, it blocked fewer electrons than the shadow mask, resulting in brighter, whiter images and more vibrant colours.