Abstract:
A liquid crystal polarization rotator device is able to rotate polarization fast enough to compensate polarization mode dispersion. The amount or degree of rotation is rapidly reconfigurable. The device includes a cavity filled with a nematic liquid crystal material. The cavity has electrodes on a first face, e.g., a first substrate, and electrodes on a second face, e.g., a second substrate, opposite the first face. The electrodes are shaped and positioned to produce an electric field across the cavity capable of rotating the alignment direction of the molecules of the liquid crystal material in the cavity. The electrodes are patterned on the ends of optical fibers. Aligning and positioning of the electrodes on the ends of the optical fibers with a predetermined spacing forms the cavity that is filled with the nematic liquid crystal material. The filled cavity is a so-called liquid crystal microcell wave plate. A control system is used to control the “rapid” rotation of the alignment direction of the molecules of the liquid crystal material. The control system receives data regarding the polarization of light entering or leaving the microcell and adjusts the direction of the electric field also using trigger pulses such as to rotate the nematic liquid crystal material molecules by a first predetermined number of degrees greater than a second desired number of degrees of rotation. Then, the trigger pulses for the electric field are stopped after the molecules have rotated by the second desired number of degrees. In this manner, the molecules rotate by the second desired number of degrees much faster than if a pulse had been applied with the same speed to rotate them by the second desired number of degrees in he first place.
Abstract:
A retractable door system for returning to a nearly closed position a door that has been opened having: a catch knob secured to a doorframe; a housing secured to a door; a retractable cord anchored within the housing at one end and having means for attaching to the catch knob at an opposite end; and a cord retracting means located within the housing for retracting the cord within the housing. The retractable door system may optionally further have a pad on the portion of the housing contacting a doorframe when the door is placed in a nearly closed position or a pad on the portion of the housing contacting a door or means for adjusting the tension of the retractable cord.
Abstract:
A method and system for rapidly initializing a rover unit in a networked system. In one embodiment, the present invention acquires rover unit initialization data at a reference station. In one embodiment, the rover unit initialization data is selected from the group consisting of: ephemeris data, almanac data, satellite health data, ionospheric data, UTC and GPS time and approximate rover position information. In the present embodiment, the present invention then communicatively couples the reference station to a server station having memory for storing the rover unit initialization data. After communicatively coupling the reference station to the server station, the present embodiment transfers the rover unit initialization data from the reference station to the server station. The present embodiment then communicatively couples the rover unit to the server station. Next, the present embodiment supplies the rover unit initialization data from the server station to the rover unit. As a result, in the present embodiment, the rover unit is able to be initialized and obtain a first position fix without requiring the rover unit to acquire the initialization data directly from at least one satellite. In another embodiment, the present invention provides a method and system for providing differentially corrected position information to a rover unit in a networked system. In still another embodiment, the present invention provides a method and system for providing both initialization data and differentially corrected position information to a rover unit in a networked system.
Abstract:
An educational visual display system for teaching geography in which objects having some geographical or topographical significance, e.g., states of the Union, may be detachably affixed and arranged to demonstrate relationship between the objects. The preferred system includes (1) a primary background surface of iron velvet fabric material to which hook type fasteners may be detachably adhered, (2) a plurality of primary objects having geographical significance and comprising a soft foam core with a layer of iron velvet fabric on one side and a plurality of hook type fasteners on the other side, the primary objects being arrangeable to represent in combination a larger geographical unit, and (3) a plurality of secondary objects each having geographical or topographical significance and having hook type fasteners on one side thereof for being detachably affixable to the layer of iron velvet fabric of the primary objects. The iron velvet fabric and the hook type fasteners function as an attachment pair similar to hook and loop fasteners sold under the tradename VELCRO.RTM..
Abstract:
For liquefying hot melt adhesive, a hopper is provided at its lower region with one or more discrete upwards projections (for example a single, fluted cone), with means for heating the projection(s). In use, a unitary mass of hot melt adhesive is lowered into the hopper to become supported on the projection(s), as a result of which the unitary mass is progressively melted and the melted adhesive flows from the bottom of the hopper.
Abstract:
An applicator head, for applying a coating of material (e.g. hot-melt adhesive) to a passing ribbon comprises an extrusion slot disposed transverse to the direction of passage of the ribbon and arranged to apply a coating of material in at least one continuous band along the ribbon, and an arrangement for intermittently opening and closing an extrusion slot for applying a coating of material discontinuously in a band contiguous with said one band.
Abstract:
Keyboard-based search of local and/or connected digital media items may be facilitated. A digital media item search interface may be presented in the same view as a messaging interface. The digital media item search interface may receive input such as from an on-screen keyboard to facilitate editing of user-provided search queries and submission of the user-provided search queries. The digital media item search interface may present digital media item tags relating to context information based on input received by the digital media item search query field. The digital media item search interface may present visual previews of local and/or connected digital media items corresponding to digital media item tags presented in the digital media item tag field. The digital media item search interface may receive user selections of individual digital media items to be communicated to one or more other users via the messaging interface.
Abstract:
Provided are methods and devices for interfacing with brain tissue, specifically for monitoring and/or actuation of spatio-temporal electrical waveforms. The device is conformable having a high electrode density and high spatial and temporal resolution. A conformable substrate supports a conformable electronic circuit and a barrier layer. Electrodes are positioned to provide electrical contact with a brain tissue. A controller monitors or actuates the electrodes, thereby interfacing with the brain tissue. In an aspect, methods are provided to monitor or actuate spatio-temporal electrical waveform over large brain surface areas by any of the devices disclosed herein.
Abstract:
Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.
Abstract:
A method of performing a retinal examination is described wherein perimetry points are selected in three dimensional imaging data of the retinal tissue. The corresponding points in register with these perimetry points are mapped to an en-face image. These corresponding points are used as stimulus locations for a micro-perimetry examination.