Abstract: Methods and apparatus are provided for reducing the visual artifacts exhibited by a display employing individually addressable pixels. The apparatus comprises an array of pixels, each pixel having a switchable region of alterable transparency or luminance and a non-switchable region. The switchable region of each pixel is distributed, that is, divided into at least two simultaneously switched portions at least partly separated by a significant portion of the non-switchable region. The first order spatial harmonics and visual artifacts are significantly reduced. For a color display, each color pixel is similarly subdivided.

Abstract: Method and apparatus are provided for displaying an image to a viewer with reduced visual artifacts. The apparatus comprises a display panel for forming the image using an array of pixels with distributed active regions, and a viewing arrangement optically situated between the display panel and the viewer for transferring the image formed on the display panel to the viewer with limited angular pixel subtense. The distributed active regions of the pixels are desirably divided into at least two simultaneously switched portions at least partly separated by or surrounding a significant portion of the non-switchable region. First order spatial harmonics and associated artifacts are reduced by the distributed apertures and second order and higher harmonics are reduced by limiting the pixel subtense angle seen by the viewer. A significant reduction in visual artifacts arising from the periodic structure of the display panel is obtained.

Abstract: An active material and light emitting device comprises an ultrasonic atomizer assembly and a light emission device. The active material and light emitting device further includes a housing containing the atomizer assembly and the light emission device such that the atomizer assembly is disposed above the light emission device. The light emission device emits light that is transmitted through a medial portion of the housing.

Abstract: Precision approach path indicator systems (PAPIs) effective in providing approach slope guidance for aircraft approaching an airport runway are provided. Such PAPIs include a plurality of light assemblies positioned on or in proximity to an airport runway and structured or configured to be effective in providing approach slope guidance light signals to a pilot of an aircraft approaching a runway. Each light assembly includes a light source comprising light emitting diodes (LEDs), preferably a first array of LEDs and a second array of LEDs.

Abstract: A light apparatus includes one or more light pipes and/or diffusers to transfer and/or diffuse light from a few point light sources to a broader area and to other points. A hollow light pipe includes a light transmissive sidewall that encompasses an interior space, which receives and hides control circuitry for the light sources therein. A bottom end surface of the hollow light pipe is disposed adjacent to one or more light sources and transmits the light therefrom over a relatively large, uniform area. A solid core light pipe has a light receiving end and a light dispersion end having a reflective facet therein. The reflective facet includes a depression forming a reflective surface angularly displaced from a longitudinal axis of the solid core light pipe. A light diffuser surrounding a point source of light is adapted to cause the point source to look like a flame.

Abstract: An image projection system has a first lens with a defined entrance pupil. An image source has an image field and a defined exit pupil. The exit pupil of the image source is configured such that the exit pupil of the image source underfills the entrance pupil of the lens for portions of the image source that are not in the center portion of the image field.

Abstract: Methods and apparatus are provided for color correction and contrast enhancement of projection displays. A visual display system includes a projector having a light source with a fixed spectral output, a display screen receiving the output of the projector and emitting a diffused output, and a color correction contrast enhancement filter positioned between the diffusing screen and a viewer. The filter differentially attenuates primary colors of the emission from the diffusing screen. The method includes projecting a light output from a light source having a fixed spectral output onto a diffusing screen, and attenuating primary colors of the emission from the diffusing screen with a light filter positioned adjacent to the diffusing screen.

Abstract: A projection system includes a vibration controlling structure. The projection system includes an imaging unit mounted to a movable platform via a partially compliant mount structure, such that the imaging unit is partially isolated from the platform while projecting an image which is stable with respect to the platform. The imaging unit and partially compliant mounting structures are constructed and arranged to damp vibrational forces on the imaging unit.

Abstract: Methods and apparatus are provided for a combined image on a head-up display. A data image display provides a first part of a combined image. An optical input provides a second part of the combined image, e.g., the background scene. A combiner superimposes the first and second parts to provide the combined image to the viewer. The data image display preferentially delivers s-polarized light to the combiner, which has a selective reflectance region for preferentially reflecting s-polarized light in a wavelength region of interest. In a preferred embodiment, the data image display comprises a backlight, a liquid crystal layer and two polarizers oriented so that the data images directed toward the combiner are s-polarized with respect to the selective reflectance region. A polarization rotation element may also be used in the data image display to facilitate s-polarization orientation.

Abstract: An image projection system has a first lens with a defined entrance pupil. An image source has an image field and a defined exit pupil. The exit pupil of the image source is configured such that the exit pupil of the image source underfills the entrance pupil of the lens for portions of the image source that are not in the center portion of the image field.

Abstract: A new lighting system is provided that is particularly useful in projecting light to a deck where pilots use night vision goggles (NVGs). The system comprises a pair of subsystems that project light with different, complementary spatial distributions. One subsystem projects light with one spatial distribution, and the other lighting subsystem projects light with another spatial distribution that supplements the light from the first subsystem, so as to provide a system that effectively illuminates an entire target. The system is designed to substantially filter light so that the light does not interfere with NVGs. The system includes new optical projection structure that minimizes the overall size of the projection structure, and maintains good efficiency.

Abstract: An image projection system has a first lens with a defined entrance pupil. An image source has an image field and a defined exit pupil. The exit pupil of the image source is configured such that the exit pupil of the image source underfills the entrance pupil of the lens for portions of the image source that are not in the center portion of the image field.

Abstract: Precision approach path indicator systems (PAPIs) effective in providing approach slope guidance for aircraft approaching an airport runway are provided. Such PAPIs include a plurality of light assemblies positioned on or in proximity to an airport runway and structured or configured to be effective in providing approach slope guidance light signals to a pilot of an aircraft approaching a runway. Each light assembly includes a light source comprising light emitting diodes (LEDs), preferably a first array of LEDs and a second array of LEDs.

Abstract: An apparatus including a spatially modulated extended light source configured to project an output having at least one region of diminished illumination, and an array of polarizing beam splitters (PBSs) positioned proximal to the spatially modulated extended light source. The light source includes at least two light outputs configured to project unpolarized light; and at least one gap interspersed between the light outputs. The array of PBSs is configured to receive the output from the light source, convert the unpolarized light to light having a first polarized state, and remove the at least one region of diminished illumination.

Abstract: A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

Abstract: A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

Abstract: Methods and apparatus are provided for chromatic vignetting in lens systems. The apparatus includes a projection lens unit having an aperture stop, and a selective filter positioned at the aperture stop. The aperture stop defines a ray bundle boundary of an image passing therethrough. The selective filter includes a transmission area having an optical perimeter based on the ray bundle boundary, and a wavelength band filter partially extending from the optical perimeter into the transmission area. The projection lens unit may be used with an illumination unit having a light source and optics conditioning the light from the light source prior to illumination of a light valve. The selective filter may optionally be positioned at a conjugate plane to the aperture stop in the illumination unit.

Abstract: An electronic dimming system for use in projection displays is provided. In a first embodiment, the dimming system comprises a first non-absorbing polarizer, a variable polarization rotator, a second non-absorbing polarizer and a heat absorber. The first non-absorbing polarizer receives light from a light source and passes the light of a selected polarization to the variable polarization rotator. The variable polarization rotator selectively rotates the polarization of the received light. The light passes from the variable polarization rotator to the second non-absorbing polarizer. The second non-absorbing polarizer passes only light of a second selected polarization. The light that passes the second non-absorbing polarizer is passed to the display, where it is used to illuminate the display. The system provides the ability to control the amount of light passed to the display by selectively rotating the polarization of the light with the variable polarization rotator.

Abstract: A screen assembly that combines an angle re-distributing prescreen with a conventional diffusion screen. The prescreen minimizes or eliminates the sensitivity of the screen assembly to projector location. The diffusion screen provides other desirable screen characteristics. Compatible screen structures, along with methods for fabricating high resolution prescreens and methods and devices for maintaining the desired relationship between the prescreen and the diffusion screen are contemplated.

Abstract: A position light (200) for use on an aircraft. The aircraft position light uses light sources (302) installed into an alignment fixture (304) which optionally carries away heat generated by the light sources. Light emitted by the light sources is directed into a first prism (308), which distributes and directs the light. A second prism (324) is used to further shape the pattern of the light. A lens (206) is installed over the position light (200) to protect it from the elements.