Abstract: Display apparatus comprising at least two projectors (1, 2) which are each for providing a display, masks (10, 11), and optical control means (3, 4, 5, 6) for controlling via the masks (10, 11) the brightness of each display across an overlap region formed by parts of the displays that overlap, the optical control means (3, 4, 5, 6) comprising an optical component (13) which spreads light and which is positioned on an illumination side of a liquid crystal display panel (3) in each projector (1, 2).

Abstract: An image projection display system for use in large field-of-view presentations, which image projection display system comprises a fold mirror arrangement and a plurality of projection devices, the image projection display system being such that light beams from the projection devices are optically combined by the fold mirror arrangement so as to appear to be projected from essentially a common equivalent eye point, whereby the displayed information of adjacent projected displays is able to be correctly aligned with respect to a design eye point without the need to apply distortion to the images.

Abstract: Optical scanning apparatus comprising a source of light, a rotatable reflecting element having a plurality of reflective facets which are inclined to the axis of rotation, a beam expander for deriving a collimated beam of light from the source, this collimated beam being directed at the reflecting element in a direction parallel to its axis of rotation to impinge upon successive facets thereof as it is rotated. The apparatus also includes a support, which may be a system of rollers, for defining a position for a recording element having a surface that requires scanning, a projection lens for focussing the collimated beam as reflected by the reflecting element onto the surface of the recording element, a motor coupled to rotate the reflecting element, so that each facet in turn causes the focussed beam to scan across the surface in one direction, and a drive for moving the recording element substantially perpendicular to the direction of scanning, past said focussed beam.

Abstract: Photocomposing apparatus comprising a projection system for projecting optical images selected from a character matrix onto a photosensitive recording member by way of a mirror which is rotatable to displace projected images with respect to the recording member. The projection system includes a wide-angle lens for focussing the optical images onto a substantially flat image plane coincident with the recording member, and a zoom lens system arranged to produce a first fixed image which provides, by the action of the rotatable mirror, an object for the wide-angle lens which is selectively positionable in a substantially flat object plane.