Abstract: A portable overhead projector comprising a rigid housing, a collapsible expansion housing, a fold mirror, a fresnel lens, a light source and a projecting head assembly. In the portable configuration of the projector, all of the operational elements of the projector are collapsed into the confines of the rigid housing. The expansion housing is a box-like assembly having two fixed and two hinged sidewalls. The first and second sidewalls are integrally formed with a bottom wall of the expansion housing. The bottom edges of the third and fourth sidewalls are attached via hinges to opposite marginal edges of the bottom wall. The top edges of the third and fourth walls are attached to the underside of the rigid housing by two hinges. The fold mirror is mounted via a hinge to the inner surface of the bottom wall. The projection head assembly which includes a projecting lens and a projection mirror is attached to the rigid housing by a post, a rack and pinion gear mechanism and a mounting arm.

Abstract: A compact podium, of substantially conventional apperance, conceals therein a video camera and optical system. Illustrative materials, inserted into a slot at the speaker's waist, fall within the field of the camera after reflection from two mirrors. A two-way mirror serves as one reflector in the optical system and also as the sloped portion of the podium. The speaker looks through the two-way mirror and sees his illustrative material which is simultaneously displayed as a video picture. There is an unobstructed line of sight between the presenter and his audience.

Abstract: A portable overhead projector has a top surface which slopes downwardly from the rear wall to the front wall and includes stops on the top surface adjacent to the front wall for preventing a transparency from sliding off the top surface during use and to preset the distance of the leading edge of the transparency from the bottom edge of the protecting wall.

Abstract: A device for supporting a transparency on a top surface of an overhead projector is foldable from a compact unit into a structure having a planar base with an indentation for receiving a transparency and legs which are pivotally mounted on the base and rest on the top of an overhead projector to position the transparency at a specific spacing therefrom. Other pivotal elements position a lens at a given distance above the base so that light from the overhead projector will pass through the transparency and project it on a remote screen without white light showing around the sides of the transparency.

Abstract: A portable overhead projector comprises a rectangular box-like housing having an open top and four side walls, a projecting lamp disposed in the housing and a planar fresnel lens. The fresnel lens is mounted in the housing for pivotal movement from a storage position wherein the fresnel lens is adjacent the open top of the housing to an operative position wherein the fresnel lens is spaced above the open top of the housing and the projecting lamp. A projecting head assembly is mounted to the housing when the fresnel lens is in the operative position to dispose the projecting head assembly thereabove and a cover is connectable to the housing for covering the fresnel lens when in the storage position.