Abstract: Multi-channel visual display apparatus comprising electronic means which is such that adjacent visual displays in a multi-channel display configuration are matched in color and hue in 2- and 3-primary color systems (FIG. 3). The apparatus may include one or more of a liquid crystal display projector (20), a cathode ray tube projector (10), and a light valve projector. A camera (30) and a front projection screen 40 are employed.

Abstract: A method of constructing a thin film mirror, which method comprises constructing the mirror from thin plastics film on a suction chamber (8) which has: (i) top and bottom edges (AA', BB') which lie on a required mirror surface; (ii) ends that each have a contact surface to the thin plastics film that lies on a required mirror surface which can be developed from a plane so that the thin plastic film is able readily to be attached; and (iii) no abrupt discontinuities in a mirror support edge part (ABC) of the suction chamber.

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: Image display apparatus comprising projector means, a first modulator and a second modulator, the first and the second modulators being such as to modulate picture elements in an image whereby finite minimum image brightness above true black is reduced, and whereby the contrast range of the projected image is extended.

Abstract: Image display apparatus (2) comprising at least one display projector for displaying an image, signal generator means for generating a control signal for controlling the intensity of the image, modulator means (4, 6) for generating a modulation waveform for modulating the intensity of the image, and adjustor means (8, 10) for adjusting the modulation waveform to improve the performance of the modulation waveform at various image intensities, the image display apparatus being such that it uses different modulation waveforms for various image intensities, it uses a proportion of at least one modulation waveform in dependence upon the control signal, and it uses the resultant modulation waveform to modulate the control signal.