摘要:
The present invention comprises various embodiments of a retroreflectometer capable of measuring the retroreflectance of a material. The retroreflectometer comprises an illumination path and a retroreflection path. The illumination path comprises focusing optics, a source aperture, a beamsplitter and a collimating lens. The retroreflection path comprises a focusing lens, a beamsplitter, a receiver aperture and a receiver. The source aperture shapes the transverse profile of the light to make it appropriate to the measurement. Focusing optics, such as a biconvex lens, may be placed between the light source and the source aperture. After the beam is reflected by the object under test, it enters the retroreflection path of the instrument. The focusing lens focuses the light through the beamsplitter and onto the receiver aperture. The receiver aperture may be the input slit for a spectrometer, or there may be optics, such as a lens or an optical fiber, that transfer the light from the aperture to the receiver. A photopically corrected detector, multiple detectors with filters or a spectrometer may be used in various embodiments of the present invention as the receiver.
摘要:
The present invention comprises various embodiments of a retroreflectometer capable of measuring the retroreflectance of a material. The retroreflectometer comprises an illumination path and a retroreflection path. The illumination path comprises focusing optics, a source aperture, a beamsplitter and a collimating lens. The retroreflection path comprises a focusing lens, a beamsplitter, a receiver aperture and a receiver. The source aperture shapes the transverse profile of the light to make it appropriate to the measurement. Focusing optics, such as a biconvex lens, may be placed between the light source and the source aperture. After the beam is reflected by the object under test, it enters the retroreflection path of the instrument. The focusing lens focuses the light through the beamsplitter and onto the receiver aperture. The receiver aperture may be the input slit for a spectrometer, or there may be optics, such as a lens or an optical fiber, that transfer the light from the aperture to the receiver. A photopically corrected detector, multiple detectors with filters or a spectrometer may be used in various embodiments of the present invention as the receiver.
摘要:
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).
摘要:
An optical unit that includes a polarizing beamsplitter (PBS). The PBS includes a reflective polarizer that transmits a portion of a light beam that has a first polarization and reflects a portion of the light beam that has a second polarization. A light absorbing device is operatively disposed relative to the PBS. The light absorbing device receives the light either transmitted or reflected by the PBS. The light absorbing device includes a light capture portion having a structured surface.
摘要:
Provided is a Fresnel lens for use with an array of semiconductor pixels that are separated by inactive areas, comprising a faceted surface with a plurality of facets for receiving an imaging beam, the facets being arranged into a plurality of zones separated by zone edges, and wherein the zone edges are generally aligned with the inactive areas throughout the array. Also provided are an optical detector and an imaging system incorporating such a Fresnel lens system.
摘要:
A lenticular polarization converter for polarizing a beam of unpolarized light is described. The polarization converter includes an input lenslet array, a polarizing stack, and an output lenslet array, all arranged sequentially and optically aligned. The input lenslet array has two major surfaces, the first of which has an array of curved surfaces to focus light and the second of which has alternating transmissive and reflective regions. The beam of light is focused by the input lenslets through the transmissive regions onto the polarizing stack. The polarizing stack transmits a first polarization component and reflects a second polarization component towards the reflective regions. The second polarization component is circularly polarized by the polarizing stack and is reflected by the reflective surfaces. The circularly polarized component passes again through the polarizing stack and is linearly polarized, allowing the component to pass through the polarizer. An output lenslet array is used to align the now polarized beam in a desired direction of travel.
摘要:
A condenser lens for a projection system optimizes the amount of overall brightness directed toward an aperture and the uniformity of illumination at the aperture. The lens, when placed in the projection system, has a marginal ray which starts at the center of the light source, passes through the edge of the condenser lens, and intersects the region to be illuminated at or near its edge. The lens further has a relative zonal ray height which is selected based on the distance from the light source to the aperture. The condensing lens system is particularly useful in the construction of overhead projectors.
摘要:
A family of condenser lenses for an overhead projector (OHP) are designed to balance overall brightness in the projected image versus uniformity of illumination. The lenses are plano-convex and aspheric, and their conic constant is a function of the radius of curvature. The radius of curvature is further selected from a range which depends upon the size of the stage of the OHP. Preferred values of other parameters of the lens and OHP optical system are selected to complement the lens design. The lens is constructed of a heat-resistant material, such as borosilicate, to withstand the high temperatures generated by the incandescent lamp within the OHP base. Condenser lenses which are members of the described family provide performance, in terms of total luminous flux and uniformity of that flux, which is superior to the performance of previous designs.
摘要:
A family of condenser lenses for an overhead projector (OHP) are designed to balance overall brightness in the projected image versus uniformity of illumination. The lenses are plano-convex and aspheric, and their conic constant is a function of the radius of curvature. The radius of curvature is further selected from a range which depends upon the size of the stage of the OHP. Preferred values of other parameters of the lens and OHP optical system are selected to complement the lens design. The lens is constructed of a heat-resistant material, such as borosilicate, to withstand the high temperatures generated by the incandescent lamp within the OHP base. Condenser lenses which are members of the described family provide performance, in terms of total luminous flux and uniformity of that flux, which is superior to the performance of previous designs.
摘要:
Light assembly (10) having reflector (16), light source (18), an outer light cover (12), and a curved transflective surface (15). Embodiments of light assemblies described herein are useful, for example, as signs, backlights, displays, task lighting, luminaire, and vehicle (e.g., cars, trucks, airplanes, etc.) components. Vehicle comprising light assemblies include those where the light assembly is a vehicle tail light assembly.