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 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'stilt angle (&bgr;) is less than 45°, which reduces astigmatism and the required back working distance of the system's projection lens (74).

Abstract: Methods are provided for optimizing the spectrum of a light source used in a projection display system in order to reduce the light loss associated with color splitting/recombination in the system. Projection systems designed in accordance with such methods are also disclosed.

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 (&bgr;) is less than 45°, which reduces astigmatism and the required back working distance of the system's projection lens (74).

Abstract: Illumination systems (11) are disclosed which provide scrolling progressive color change on a liquid crystal panel (21), such as a LCoS panel. The systems use transmissive color filters (30, 31, 33) which form an assembly (13) which is rotated about a rotation axis (37). Incident light from a light source (15, 17) passes through the filters and reflects from a reflecting surface (39). As a result of this reflection, the system's optical axis (41, 43) is turned from an orientation substantially perpendicular to the rotation axis to an orientation which does not intersect a filter. Such turning of the optical axis allows colored light to be easily removed from the assembly and avoids problems with color mixing at boundaries between filters as occurs for systems in which light passes through two filters.

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 (&bgr;) is less than 45°, which reduces astigmatism and the required back working distance of the system's projection lens (74).

Abstract: Illumination systems (11) are disclosed which provide scrolling progressive color change on a liquid crystal panel (21), such as a LCoS panel. The systems use transmissive color filters (30, 31, 33) which form an assembly (13) which is rotated about a rotation axis (37). Incident light from a light source (15, 17) passes through the filters and reflects from a reflecting surface (39). As a result of this reflection, the system's optical axis (41, 43) is turned from an orientation substantially perpendicular to the rotation axis to an orientation which does not intersect a filter. Such turning of the optical axis allows colored light to be easily removed from the assembly and avoids problems with color mixing at boundaries between filters as occurs for systems in which light passes through two filters.