U.S. Philips Corporation

Adrianus H Van Den Brandt

Adrianus J De Vaan

Wilhelmus A Timmers

An illumination device for supplying a beam of linearly polarized light having a non-rotationally symmetrical cross-section at the location of an object to be illuminated is described, which device comprises a light source, a reflector, an optical integrator (54, 82) for forming said beam cross-section and for realizing a uniform light distribution across the beam cross-section, and a polarizing system for converting the light supplied by the source into linearly polarized light. Since the polarizing system is arranged in the radiation path in front of the optical integrator, the device can be implemented with a small number of components and in a compact manner. The device may be used to great advantage in an image projection apparatus.

High-efficiency illumination device and image projection apparatus

An image projection apparatus is described, which comprises an illumination system (100, 101, 54, 57, 62) having a first, round lens plate (54) and a second, half-round lens plate (57). A combination of a special polarization-sensitive beam splitter (20) and a polarization rotator (31) is arranged in the path of the beam supplied by this system and converts the beam into two sub-beams having the same state of polarization which jointly illuminate a display panel (1) in a uniform manner and optimally fill the surface area of this panel and a subsequent projection lens system (C).

Image projection apparatus

An efficient illumination system for an image projection apparatus is described, which system comprises a radiation source (20), a concave reflector (21) and a first and a second lens plate (25, 28) each being provided with a matrix of lenses (26, 29) for forming superimposed images of the radiation source on the object (1) to be illuminated, the aspect ratio of the lenses (26, 29) corresponding to that of the object (1).

Optical illumination system and projection apparatus comprising such a

A projection system comprises a plurality of reflective LCDs (41, 42, 43) which are irradiated with colored sub-beams (21, 22, 23). The sub-beams are not perpendicularly incident on the LCDs so that the reflected beams (24, 25, 26) do not coincide with the incident beams. The sub-beams originate from a white light beam (20) which is split up into colored sub-beams by means of color-selective mirrors (31, 33). The same mirrors are used to combine the reflected beams (24, 25, 26) to a projection beam (27). An angle-dependent beam separater (80) is arranged so as to realize a spatial separation between the incident beams and the reflected beam. The angle-dependent beam separater (80) is arranged in such a way that the angle at which the beam (20) is incident on the color-selective mirrors (31, 33) is equal to the angle at which the reflected sub-beams (24, 25, 26) are incident on these mirrors.

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Eindhoven, Netherlands

Adrianus H Van Den Brandt