US 4,416,520 AGranted

Slide projector having two image-projection systems which operate with a single slide tray

AssigneeSource Technologies, LLC

InventorMilo G. Kramer

Life of this patent

Estimating the term…

Loading patent…

Abstract

The slide projector includes side-by-side image-projection systems and a circular slide tray, with slides passing in operation directly between the slide tray and either of two slide gates, the slide gates moving between a first position in which slides are acquired and released, and a second position in which slides are projected onto a screen. A slide lifter, a slide tray lock, slide clamps on each slide gate, and the slide gates are operated in a particular sequence relative to the movement of the slide tray to insure proper handling of the slides in the projector. The slide tray fits on a central hub which in turn is independently driven. Sensors are provided to continuously detect the position of the lifter, the slide gates, and the slide tray. A front end assembly which incorporates lenses which move laterally and vertically, with the longitudinal axes of the lenses remaining parallel at all times, provides precise image alignment, including image overlap and separation.

Claims4

Dependent claims

In a multiple image slide projector which includes a projector housing and first and second image projection systems which in turn each include a projection lens, a portion of the projection lens being within the projector housing, wherein each image projection system projects slides acquired from a slide tray onto a screen, an apparatus for precisely aligning the images on the screen, comprising:

mounting boxes positioned within the projector housing for supporting each projection lens, said mounting boxes substantially surrounding the longitudinal dimension of the portion of its projection lens which is within the projector housing;
mounting plates for each mounting box, secured to the front end of the mounting box, the mounting plates having an opening therein through which the projection lens extends;
means within the projector housing for supporting said mounting plates in the vicinity of the front of the projector for lateral movement thereof;
and
means for moving the images on the screen by moving at least one of said mounting plates, which in turn results in corresponding movement of the mounting box secured thereto and its projection lens, the direction of movement of said one mounting plate being at a substantially right angle to the longitudinal axes of the image projection systems.

2 more elements

Dependencies are inferred from the claim text.