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 rear projection screen for use with a projection lens which has an exit pupil (23) is provided. The screen has a light entering side and a light exiting side and comprises in order from said light entering side to said light exiting side: (a) a Fresnel structure (11); (b) a lenslet array (13); and (c) an opaque layer (15) comprising a plurality of pinholes, said pinholes being at locations which correspond to the images of the exit pupil formed by the combination of the Fresnel structure and the lenslet array.

Abstract: A lens assembly adapted to be connected to a CRT and affixed to mounting structure in a projection television cabinet. The lens assembly includes a tubular lens mount having a longitudinal axis and at least a first optical lens element mounted along the longitudinal axis. A tubular focus mount extends along the longitudinal axis and fastening and locking structure connects the lens mount to the focus mount after a focus mount position is obtained. A CRT coupler is formed integrally with the focus mount and includes structure for securing a CRT and for securing the coupler to the mounting structure within the television cabinet. A second optical lens element is mounted to the CRT coupler. A flexible bladder may be used to contain coolant fluid between the CRT and the coupler.

Abstract: Apparatus and methods for mounting and aligning the optical elements of a light engine (20) for a projection image display system (21) to produce a focused, converging, high-resolution and coherent full-color image with optimized contrast and brightness. The optical elements of an illumination subsystem of the light engine are aligned to optimize the efficiency and properties of light transferred from a light source (26) to a set of three imagers (38, 40, 42). The optical elements of a projection subsystem (24) of the light engine (20) are aligned to optimize the synthesis of the three primary color components output by the imagers (38, 40, 42) to project the full-color image onto a projection screen. The alignment is achieved by apparatus and methods that accurately position the optical elements and that precisely adjust the relative positions and angular orientations of certain of the 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'stilt angle (&bgr;) 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'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: 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: Optical systems for use with reflective LCDs (8,9,32,34,36) are provided. The systems include a polarization beam splitter (5) which can be composed of polarization beam splitting cubes (26) having sheet polarizers (30) and/or half wave plates (28) at their mating surfaces. By orienting the half wave plates (28) so that they convert S polarization to P polarization and P polarization to S polarization, the polarization beam splitter (5) can provide a high contrast ratio at a viewing screen between light from the “on” and “off” pixels of the reflective LCDs (8,9,32,34,36).