Abstract: An image projection system includes an image generator and first and second projection screens. The image generator respectively generates the first and second portions of the image on the first and second projection screens. The first projection screen projects the first portion of the image in a first color, and the second projection screen projects the second portion of the image in a second color. Such an image projection system is often less complex and less expensive than a conventional image projection system such as a projection television system. In addition, such a projection system often provides a higher-quality image than a conventional image projection system.

Abstract: An optical image system includes an image projector and an image generator. The image projector has regions with adjustable brightness levels. The image generator generates an image received from a remote location on the image projector by directing first and second electromagnetic beams onto the regions of the image projector. The first beam changes the brightness levels of the regions in a direction, and the second beam generates the image by changing the brightness levels of predetermined ones of the regions in an opposite direction. Such an image system can capture, transmit, and display an image using an optical signal without converting the optical signal into an electrical signal and back again. Thus, the image system often provides a higher-quality image than conventional electro/optical image systems.

Abstract: An image system includes a beam generator and a screen having a region with an adjustable brightness. The beam generator directs first and second electromagnetic beams onto the region. The first beam changes the brightness of the region according to a first polarity and the second beam changes the brightness of the region according to a second polarity. Such an imaging system can generate a video frame on a projection screen such that each pixel of the frame is “on” for the same or approximately the same amount of time as each of the other pixels. This technique prevents portions of the image from appearing visibly dimmer than other portions. It also allows the persistence of the screen regions to be relatively long, e.g., longer than the frame rate, and thus allows the screen to display/project relatively high-quality video frames.

Abstract: A display apparatus includes an image source, an eye position detector, and a combiner, that are aligned to a user's eye. The eye position detector monitors light reflected from the user's eye to identify the pupil position. If light from the image source becomes misaligned with respect to the pupil, a physical positioning mechanism adjusts the relative positions of the image source and the beam combiner so that light from the image source is translated relative to the pupil, thereby realigning the display to the pupil. In one embodiment, the positioner is a piezoelectric positioner and in other embodiments, the positioner is a servomechanism or a shape memory alloy.

Abstract: A scanning control circuit generates a clock signal corresponding to an expected scan timing of a resonant scanner. In one approach, the control circuit uses a pair of direct digital synthesis (DDS) integrated circuits. A first DDS chip provides a system clock that is synchronized to the monitored period of the scanner. A second DDS chip generates a frequency chirped signal that has a frequency profile corresponding to a desired pixel clock timing. To control phase precisely, four complementary clock signals are weighted and mixed at light source drivers to produce relative phase shifts for different light sources.

Abstract: An antenna (20) operable over a predetermined range of frequency includes a transmission line (36), a transformer network (42) connected to one end of the transmission line, and at least one inductor-resistor network (46) connected to an opposite end of the transformer network. The inductor-resistor network (46) changes the effective electrical length of the antenna (20) such that as the frequency of operation changes, the current distribution above and below the inductor-resistor network changes in a corresponding manner. A second inductor-resistor network (56) may be serially connected to the other network (46), wherein both function to reduce the current thereabove. Accordingly, as the frequency of operation increases, the electrical height of the antenna decreases.

Abstract: A display apparatus includes an image source, an eye position detector, and a combiner, that are aligned to a user's eye. The eye position detector monitors light reflected from the user's eye to identify the pupil position. If light from the image source becomes misaligned with respect to the pupil, a physical positioning mechanism adjusts the relative positions of the image source and the beam combiner so that light from the image source is translated relative to the pupil, thereby realigning the display to the pupil. In one embodiment, the positioner is a piezoelectric positioner and in other embodiments, the positioner is a servomechanism or a shape memory alloy.

Abstract: A display apparatus includes an image source, an eye position detector, and a combiner, that are aligned to a user's eye. The eye position detector monitors light reflected from the user's eye to identify the pupil position. If light from the image source becomes misaligned with respect to the pupil, a physical positioning mechanism adjusts the relative positions of the image source and the beam combiner so that light from the image source is translated relative to the pupil, thereby realigning the display to the pupil. In one embodiment, the positioner is a piezoelectric positioner and in other embodiments, the positioner is a servomechanism or a shape memory alloy.

Abstract: A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The light sources are positioned such that their beams each illuminate discrete regions of the image field that are substantially non-overlapping with respect to the other discrete regions. The image is thus formed from a set of “tiles”. By activating a first light source during a forward sweep of the mirror and activating a second light source during a reverse sweep of the mirror, two halves a common line can be written during a single sweep of the mirror. Shifting the position of the sources such that the two halves are aligned reduces raster pinch. In alternative embodiments, the same approach is used for imaging.

Abstract: A display apparatus includes a scanning assembly that scans about two or more axes, typically in a raster pattern. A plurality of light sources emit light from spaced apart locations toward the scanning assembly such that the scanning assembly simultaneously scans more than one of the beams. The light sources are positioned such that their beams each illuminate discrete regions of the image field that are substantially nonoverlapping with respect to the other discrete regions. The image is thus formed from a set of “tiles”. By activating a first light source during a forward sweep of the mirror and activating a second light source during a reverse sweep of the mirror, two halves a common line can be written during a single sweep of the mirror. Shifting the position of the sources such that the two halves are aligned reduces raster pinch. In alternative embodiments, the same approach is used for imaging.

Abstract: A bouncing ball scanner is described which is a ball driven in a reciprocal motion for reflecting image-bearing light onto a photosensitive medium. The image-bearing light can be dictated by a computer, in which case the photosensitive medium may be film for a printed output, or the image-bearing light may be reflected from a subject having an image imprinted thereon, and the photosensitive medium may be a charge coupled device where the image is being read into a computer. The bouncing ball scanner comprises a ball being driven in a reciprocal motion by electromagnetic forces acting thereon. The motion of the bouncing ball is substantially linear in each direction so as to allow ease of calculation of ball position thereby ease of knowledge of pixel position on the photosensitive medium.

Abstract: An antenna (100) operable over a predetermined broad band and connected to a transmission line (102) includes a tip radiator (106) having a series capacitance (129) and a base radiator/choke (104) operatively connected to the tip radiator for changing feed point reactance values to values that provide a desired bandwidth to minimize the antenna's voltage standing wave ratio (VSWR) over frequencies in the predetermined broad band. The antenna also includes a choke assembly (108) operatively connected to the transmission line for suppressing current below a predetermined point of the antenna to maintain the desired bandwidth and VSWR.

Abstract: An optical apparatus for converting an incoming array of light beams by interchanging the horizontal and vertical components of each beam, the apparatus having a series of grooves, one groove for each incoming beam, where each groove comprises two reflecting surfaces: a first reflecting surface operating to intercept the corresponding beam and reflect it to a second reflecting surface along a first path of travel, that is folded with respect to the incoming beam's direction of propagation, while rotating one of the beam's azimuths, and the second reflecting surface operating to intercept the beam reflected off the first surface and to direct it along a second path of travel, folded with respect to the first path of travel, while rotating the beam's other azimuth.

Abstract: A hollow, tapered, fiber-reinforced plastic utility pole, and a method for making the pole. The pole is designed by a computer-modelling technique that simulates applying resin-coated, reinforcing strands over the outer surface of a mandrel. A plurality of test stations are incrementally spaced from the tip portion to the butt portion of the pole simulated on the mandrel. The thickess-to-diameter ratio must be equal to or greater than an established constant at each station or additional circuits of resin-coated, reinforcing strands deemed to have been applied, as required. One then calculates the stress resistance at each successive station to determine if the acceptable stress is greater than the stress resistance required. Whatever additional circuits of resin-coated, reinforcing strands are necessary are then deemed to have been applied.

Abstract: A high-power optical fiber device comprising a pump source of light-emitting facets, optical means for collimating and converging the array, an optical beam rotator for transforming the array by rotating individual light emissions, and an optical fiber structure having a core surrounded by an inner cladding for transferring pump energy into the core, the inner cladding having a cross-sectional shape in the form of a convex polygon.

Abstract: A breakaway utility pole (9, 109) mounting structure. The mounting structure presents a base portion (11', 16 or 20) within which the end portion (10, 110) of the pole (9, 109) is telescopically received. The base portion (11', 16 or 20) of the mounting structure extends below ground level, and an adhesive material (17, 117) bonds the pole end portion (10, 110) to the base portion (11', 16 or 20). The adhesive material (17, 117) is adapted to fail when the pole (9, 109) is subjected to an impact at a predetermined distance above ground level from a vehicle of predetermined minimum weight moving at a predetermined minimum speed.

Abstract: A low-profile, broad band monopole antenna (10) includes two linear radiators (11,13), a resistor network (18), and a transmission line network (20), all connected in series in that order. Linear radiator (11) includes a capacitor (12) which reduces the apparent electrical length of the antenna and provides high voltage isolation. Resistor network (18) reduces VSWR at lower frequencies in the band of interest such that in combination with the other elements, the VSWR for antenna (10) is sufficiently low that no further matching or tuning is necessary over the entire broad frequency band of interest without significant loss of gain relative to that of a monopole antenna one-quarter wave resonant at each frequency throughout the frequency band of interest.

Abstract: Method and apparatus for controlling an instrument which can perform a specified cyclic process. The instrument's process is controlled by a computer which has two concurrently defined tasks: an operator task for running an instrument control program, and a compiler task for compiling new instrument control programs input by the instrument's user. The currently running program is suspended and a new program's execution is begun when (a) a new program has been successfully compiled by the compiler, and (b) the current program is about to perform a jump back at the end of an instruction loop. When a main instrument control program finishes executing, a new program is run if a new program has been successfully compiled; otherwise, execution of the most recently suspended program resumes. Thus a newly compiled program interrupts the currently running program only between instruction loops, and only as long as necessary to execute its instructions.

Abstract: A breakaway utility pole (9, 109) mounting structure. The mounting structure presents a base portion (11', 16 or 20) within which the end portion (10, 110) of the pole (9, 109) is telescopically received. The base portion (11', 16 or 20) of the mounting structure extends below ground level, and an adhesive material (17, 117) bonds the pole end portion (10, 110) to the base portion (11', 16 or 20). The adhesive material (17, 117) is adapted to fail when the pole (9, 109) is subjected to an impact at a predetermined distance above ground level from a vehicle of predetermined minimum weight moving at a predetermined minimum speed.

Abstract: A low-profile, broad band monople antenna (10) includes two linear radiators (11,13), a resistor network (18), and a transmission line network (20), all connected in series in that order. Linear radiator (11) includes a capacitor (12) which reduces the apparent electrical length of the antenna and provides high voltage isolation. Resistor network (18) reduces VSWR at lower frequencies in the band of interest such that in combination with the other elements, the VSWR for antenna (10) is sufficiently low that no further matching or tuning is necessary over the entire broad frequency band of interest without significant loss of gain relative to that of a monopole antenna one-quarter wave resonant at each frequency throughout the frequency band of interest.