Slide cube projector

The Slide Cube Projector is a slide projector and system, manufactured and marketed by Bell & Howell introduced in 1970 and marketed through the 1980s. The projector derived its name from its transparent plastic slide storage cube-shaped magazine, about 5.5 cm in each dimension (a bit larger than a slide), that held 36 to 44 slides, depending on the mount thickness. The magazine had a sliding lid to hold the slides in place. The system consisted of Slide Cubes and a projector designed to use them. Bell and Howell subsequently introduced a Slide Cube Projector II, with revised features.

Unlike trays used in straight-tray or carousel slide projectors, the slides in a Slide Cube are stacked on top of each other rather than stored in separate slots. when a cube is manually set into the PRE-LOAD position and slid into the LOAD position, its lid opens. The advance trigger is activated, a sequence is initiated when the slide is advanced into the LOAD position. The advance mechanism allows one slide to drop from the loaded cube into a slide-size hole in a circular turntable to rotate through the next four positions. The turntable is thinner than one slide and is designed to allow one slide to drop and move forward to the PREVIEW, PROJECTION, and then RETURN positions. It can be returned from the RETURN position to allow for a single slide's worth of backup, and then finally to a RELOAD position, where it drops into a stack. After the slides have been viewed the operator presses a lever which lifts the slides back into the cube.

The projector used a 300 watt 120V Halogen bulb model ELH as a light source, and could optionally be operated by a wired remote control. The projector had an integrated handle, plastic lid or optional lid which incorporated additional cube storage. An adjustable foot allowed projector elevation adjustment.

Bell and Howell Slide Cubes were less expensive than trays and provided higher and cheaper storage capacity, with a book or drawer of 16 forty-slide cubes (640 slides) occupying the same space as a single round tray holding at most 140 slides. Stack storage and preview made for easier editing of slide shows; slides could be added to or removed from the show without having to move all of the remaining slides to fill the gap. Some tray-based projectors (e.g. some Kodak round-tray and Hähnel straight-tray slide projectors) could use stack loaders to view a stack of slides, but did not allow addition or removal of slides, and did not have an associated storage system.

Drawbacks of the slide cube included the inability to go back by more than one slide, the fragility of the cubes, and the advancing plate's tendency to jam if a slide mount was not perfect, interrupting slide shows and making the projectors challenging to operate.

Slide Cube Projectors are no longer manufactured, but second-hand cubes, bulbs, a few replacement parts, and complete used projectors are sold.