Giant screen color TVs are no longer the novelty they were a few years ago. There are now half a dozen manufacturers making TV projectors to display TV pictures up to six feet wide—eight to twelve times as big as the picture on a conventional set. These projectors are priced from $900 to $4,000, but only one of them is worth the investment; the rest are nothing more than clever ruses.

The picture on a normal TV set is displayed on a screen which is really the end of a giant vacuum tube, the “picture tube” in the parlance of TV repairmen. There are physical lirtiits to the size to whi£h these glass tubes can be blown—the largest TV screens of conventional sets rarely exceed 25 inches measured diagonally. Most TV sets have 19 to 21 inch screens. Manufacturers have not been able to overcome the deterioration in picture quality that seems inherent in 25 inch plus picture tubes; although Sony claims they will introduce a 25 inch Trinitron next year.