Abstract: There is disclosed an apparatus, for an interactive system including a display region, arranged to detect the position of a contact point on the display region.

Abstract: Multi-directional optical elements are disclosed that include a body having a first side having a first curvature, a second side having a second curvature, a third side having a third curvature, and a fourth side having a fourth curvature. The second side is disposed generally opposite the first side along a first direction and a fourth side is disposed generally opposite the third side along a second direction, the second direction being different from the first direction. Also disclosed are optical systems utilizing such multi-directional optical elements.

Abstract: An illumination system, such as might be used for illuminating a projection system, includes at least a first source of incoherent light capable of generating light in a first wavelength range. The system also includes a body containing a fluorescent material that emits light in a second wavelength range, different from the first wavelength range, when illuminated by light in the first wavelength range. The body has an extraction area and at least some of the light at the second wavelength is internally reflected within the body to the extraction area.

Abstract: Illumination systems are disclosed, which include illumination channels of different colors and at least one image-forming device. Each illumination channel, in turn, includes a bank of light sources, and the image-forming device is disposed to receive illumination from at least one of the illumination channels. At least one of the illumination channels includes an optical element, such as an optical element having optical power or a homogenizing optical element, that is not shared with any other illumination channel and is preferentially constructed or preferentially positioned for the color of its illumination channel.

Abstract: Illumination systems are disclosed that include a light source or a bank of light sources having a non-radially symmetrical aperture having a longer dimension and a shorter dimension, such that the light source or bank of light sources produces illumination with a non-radially symmetrical angular intensity distribution having a larger angular dimension and a smaller angular dimension. The illumination systems include an integrator having an entrance end optically connected to the bank of light sources, an exit end, and a dimension that experiences a larger increase from the entrance end to the exit end. The integrator is disposed so that the dimension experiencing the larger increase is substantially aligned with the larger angular dimension of the illumination produced at the entrance end of the integrator.

Abstract: Multi-directional optical elements are disclosed that include a body having a first side having a first curvature, a second side having a second curvature, a third side having a third curvature, and a fourth side having a fourth curvature. The second side is disposed generally opposite the first side along a first direction and a fourth side is disposed generally opposite the third side along a second direction, the second direction being different from the first direction. Also disclosed are optical systems utilizing such multi-directional optical elements.

Abstract: A compound polarization beam splitter (33) for use with a reflective, polarization-modulating, imaging device (10), e.g., a LCoS device, is provided. The compound PBS has: (a) an input prism (20); (b) an output prism (30), and (c) a polarizer (13), which is located between the two prisms (20,30) and which may be a wire grid polarizer (13a) or a multi-layer reflective polarizer (13b). Polarized illumination light (11) enters the input prism (20) through a first surface (21) and undergoes total internal reflection at a second surface (22) before being reflected from the polarizer (13) and polarization-modulated at the imaging device (10). The polarizer's tilt angle (?) is less than 45°, which reduces astigmatism and the required back working distance of the system's projection lens (74).

Abstract: A light amplification device comprises a laser slab and optics for establishing an optical beam at the lasing wavelength. The beam travels inside the slab in a zig-zag path between two reflecting faces. The slab is also cooled through the reflecting faces. The slab is pumped through one or more pumping faces, each pumping face being distinct from the reflecting faces. Light from the pump is incident upon the slab in a direction that is transverse to the plane of propagation of the lasing wavelength beam. This arrangement separates the cooling interfaces from the pumping interfaces. Distortions in the beam due to thermal effects are largely averaged out by the zig-zag path. The device may function as either a laser or an optical amplifier.