Abstract: A tiled monitor system is implemented with a single controller that does not provide standard video signals to each of the monitors. Instead, only the changed portions of an image to be displayed are sent to the monitors, which internally maintain a video frame buffer for displaying using a display engine. Preferably, a high speed serial link is used between the monitors and the video controller for transmitting this information.

Abstract: In a reflective mode FLC application, a ¼-wave plate compensating FLC is used in series with a ¼-wave imaging FLC to compensate for the effects of DC balancing. Alternatively, the compensating wave plate could be any odd ¼-wave multiple, such as 3&lgr;/4, 5&lgr;/4, etc. The FLCs are driven in synchronization between on and off states with the total effective retardation for each FLC being either none or one-half wavelength in a double pass.

Abstract: In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is used. In the system of the present invention, each pixel has three storage devices to hold RGB analog levels. A latch is used to load these values in parallel. Then an analog 3:1 multiplexer is used to select the proper storage device for the current sequential color. The multiplexer output goes to a comparator, which has a sawtooth waveform input at much faster than the frame rate. The comparator output changes with the sawtooth level, so that PWM control is provided for each pixel. As an alternative, standard analog LCD pixels can be sequentially switched between three color input storage devices.

Abstract: A light projection engine uses a wide angle reflecting polarizer material (preferably 3M DBEF brand double brightness enhancement filter) as a polarizing beamsplitter to direct polarized light to beam splitter/combiner (such as an X-cube dichroic reflector). The beam splitter/combiner then splits the directed polarized light into separate reflective LCD panels acting as light valves. The LCD panels alter the polarity of the incident light from 0 degrees up to 90 degrees to control which light is passes from the wide angle reflecting polarizer back towards the light source and which light has the necessary polarization change to allow it to pass from the wide angle reflecting polarizer to the lens system. After reflecting off of the LCD panels, the light goes back through the X-cube dichroic reflector, where it is recombined.

Abstract: An electrodeless lamp (10) for producing an intense beam of light includes a concave lamp body (11) that surrounds the lamp interior. A gas, such as sulfur or selenium or compounds thereof, is contained within the lamp body (11) for forming a plasma light source. The concave lamp body (11) has a reflecting surface (12). Electrodes (27, 28) are disposed external to the lamp body for producing radio frequency energy exciting the gas. A heat resistant glass plate (20) seals the concave lamp body (11). A frit seal (23) can be used for forming a pressure and temperature resistant seal between the concave lamp body (11) and the glass plate (20). The light beam generated by the plasma exists through the glass plate (20).

Abstract: A polymer dispersed liquid crystal projection display is provided that has enhanced contrast. In the projection system using a polymer dispersed liquid crystal display (PDLC), polarized light is used as the light source onto the PDLC. The reflected light maintains its polarization, while the scattered light from the off pixels of the PDLC randomize the polarization. The polarized image is then passed through a polarizing filter which eliminates half of the scattered light, whereas practically all of the polarized image is passed onto the display source. In this way, the contrast between the on and off pixels is effectively doubled.

Abstract: In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is used. In the system of the present invention, each pixel has three storage devices to hold RGB analog levels. A latch is used to load these values in parallel. Then an analog 3:1 multiplexer is used to select the proper storage device for the current sequential color. The multiplexer output goes to a comparator, which has a sawtooth waveform input at much faster than the frame rate. The comparator output changes with the sawtooth level, so that PWM control is provided for each pixel. As an alternative, standard analog LCD pixels can be sequentially switched between three color input storage devices.

Abstract: A full color image projection system is provided using two non-color-specific image sources and color-specific filters. The system is capable of projecting an image using one primary color from one image source and the other two primary colors from another image source. The system uses slower speed image sources than would be required with one source alternating between three colors, and exhibits higher resolution than would be obtained from a color-specific image source.

Abstract: Color shutters that include reflecting linear polarizers can be used in projection display applications. The reflecting linear polarizers are used to reflect the light that would have been absorbed by prior art color shutters. The use of reflecting linear polarizers can resolve overheating and degradation problems of prior art system and projection display systems using sequential color operation can be built and operate reliably.

Abstract: An “extra-folded” projection display system includes a selectively reflective material (e.g., a linear reflecting polarizer) placed immediately behind the system's imaging screen. The display system includes an image projector that projects an image beam containing light of a predetermined linear polarization toward the imaging screen. The linear reflecting polarizer reflects the light in the image beam away from the screen. The reflected image beam then encounters a ¼-wavelength achromatic retarder which converts the linear polarization to circular polarization. The image beam next hits a mirror that reflects the light back through the ¼-wavelength achromatic retarder, which converts the circular polarization back to linear polarization, with the polarization director rotated 90° from the original polarization director. The linear reflecting polarizer then allows the light to pass through to the image screen.

Abstract: A method of determining an object's position and associated apparatus provides positional information in a form that may be conveniently communicated to a computer system to calculate the object's position. In a disclosed embodiment, representatively incorporated in a computer keyboard, a method of determining an object's position includes forming an optical grid of overlapping beacons and detecting reflections of the beacons produced by the object when it intersects the grid. The disclosed embodiment utilizes two focused beacons to produce the optical grid.

Abstract: In a color sequential system using LCDs, the LCD must operate faster than the frame rate because red, green, and blue are done sequentially. Ferroelectric LCDs can do this, but they are not analog devices and so cannot provide analog display levels. Instead, a pulse width modulation (PWM) technique is used. In the system of the present invention, each pixel has three storage devices to hold RGB analog levels. A latch is used to load these values in parallel. Then an analog 3:1 multiplexer is used to select the proper storage device for the current sequential color. The multiplexer output goes to a comparator, which has a sawtooth waveform input at much faster than the frame rate. The comparator output changes with the sawtooth level, so that PWM control is provided for each pixel. As an alternative, standard analog LCD pixels can be sequentially switched between three color input storage devices.

Abstract: A lamp apparatus includes an electrodeless bulb that includes a chamber, a gas contained within the chamber in the bulb, and at least one reflector electrode adjacent the bulb for transmitting radio-frequency electromagnetic energy to the gas in the bulb to excite the gas and cause it to radiate light and for reflecting the light radiated from the bulb. Preferably, there are two reflectors electrodes. The bulb can advantageously be made of a tube, in which case the reflectors electrodes can be made shorter than the bulb and centered thereon so that the intense heat caused by the plasma when the gas is excited does not reach the ends of the bulb.

Abstract: A method of determining an object's position and associated apparatus provides positional information in a form that may be conveniently communicated to a computer to calculate the object's position. In a preferred embodiment, representatively incorporated in a computer keyboard, a method of determining an object's position includes forming an optical grid of reflected beacons and detecting an obstruction of the reflected beacons. The preferred embodiment apparatus utilizes a single light source and a single light sensor to detect an object's position in two dimensions.

Abstract: An electrodeless lamp apparatus of high efficiency employs a reflection system that allows the lamp to reabsorb light energy. The energy is redirected back to the light to provide increased system efficiency. The redirected light is of the wrong polarization and/or wrong parts of the color spectrum. The lamp efficiency is increased because of the optical pumping as well as the reuse (after some downshifting) of the returned light. In one embodiment, a projection system provides an image source or projection engine that includes the improved high efficiency lamp of the present invention.

Abstract: A method of determining an object's position and associated apparatus provides positional information in a form that may be conveniently communicated to a computer to calculate the object's position. In a preferred embodiment, representatively incorporated in a computer keyboard, a method of determining an object's position includes forming an optical grid of reflected beacons and detecting an obstruction of the reflected beacons. The preferred embodiment apparatus utilizes a single light source to detect an object's position in two dimensions.

Abstract: A method of determining an object's position and associated apparatus provides positional information in a form that may be conveniently communicated to a computer to calculate the object's position. In a preferred embodiment, representatively incorporated in a computer keyboard, a method of determining an object's position includes forming an optical grid of reflected beacons and detecting an obstruction of the reflected beacons. The preferred embodiment apparatus utilizes a single light source and a single light sensor to detect an object's position in two dimensions.

Abstract: A light pipe used for backlighting liquid crystal displays has a planar front surface and a stair-stepped or faceted back surface. Light is injected from the ends of the light pipe from cold- or hot-cathode, apertured, fluorescent lamps. The cold-cathode lamps are preferably insulated to raise their operating temperature. The back surface has a series of planar portions parallel to the front surface connected by facets, which are angled so that the injected light reflects off the facets and through the front surface. A reflector having a planar, highly reflective, highly scattering surface or a sawtoothed or grooved upper surface in located adjacent to and parallel with the light pipe back surface to reflect light escaping from the back surface back through the light pipe to exit the front surface. The axis of grooves is preferably slightly skewed from the facet axis to reduce moire pattern development.

Abstract: A light pipe used for backlighting liquid crystal displays has a planar front surface and a stairstepped or faceted back surface. Light is injected from the ends of the light pipe from cold or hot cathode, apertured, fluorescent lamps. The cold cathode lamps are preferably insulated to raise their operating temperature. The back surface has a series of planar portions parallel to the front surface connected by facets, which are angled so that the injected light reflects off the facets and through the front surface. A reflector having a planar, highly reflective, highly scattering surface or a sawtoothed or grooved upper surface is located adjacent to and parallel with the light pipe back surface to reflect light escaping from the back surface back through the light pipe to exit the front surface. The axis of grooves is preferably slightly skewed from the facet axis to reduce moire pattern development.

Abstract: Light sources include an electrodeless bulb having an interior, a fill contained within the interior of the bulb, an excitation structure that transmits electromagnetic energy to the fill in the bulb, and cooling fins extending radically outward from the bulb. The fill is excited by the electromagnetic energy to a plasma state that causes light emission and generates heat energy. The cooling fins, when rotated, draw air toward the bulb to cool the bulb. Alternatively, cooling may be provided by a rotatable squirrel cage about an electrodeless bulb. The light sources can be used in display systems, such as field sequential color systems.