Reveo, Inc.

Other

Meiryo Tekunika Kabushiki Kaisha

Zhan He

Sadeg Mustafa Faris

Susumu Sato

Yoshihiro Togashi

Ying Zhou

Jaujeng Lin

A novel backlight is provided for a liquid crystal display (LCD). The backlight of this invention includes an organic electroluminescent (EOL) device and a cholesteric liquid crystal (CLC) polarizing device. This invention is also an LCD. The backlight of the present invention provides for highly efficiency and bright LCDs. This invention further provides for the production of ultra-thin and lightweight LCDs.

Backlight units for liquid crystal displays

Variable optical attenuators (VOAs) are provided, based on electrically switchable CLC reflective polarizers. The reflectivity of the described reflective VOAs can theoretically be electrically adjusted between 0% to 100%, and the reflective bandwidth can be easily adjusted. In general, the VOA includes a pair of switchable CLC polarizers and a driver for driving the polarizers. When the electric fields on both polarizers are off, the polarizers serve as two reflective mirrors. When the fields are turned on, the two polarizers are switched into two transparent sheets allowing light to transmit therethrough. Continuously changing the voltages on the two polarizers electrically adjusts the attenuation.

Variable optical attenuator based on electrically switchable cholesteric liquid crystal reflective polarizers

The present invention is directed to an image display system for displaying an image in a user's line of sight including an image combiner that is electrically actuatable. The image display system generally includes an image projection device, and an electrically actuatable image combiner. The image combiner may be superposed with a transparent substrate such as a visor or a windshield.

Image display system and electrically actuatable image combiner therefor

The disclosed invention is a novel polarized light source. The polarized light source of this invention includes an organic electroluminescent (OEL) device or an organic photoluminescent (PL) device and a cholesteric liquid crystal (CLC) polarizing device. The polarized light source of the present invention is an efficient, high purity, and bright source of polarized light. Further, the present invention enables a polarized light source to be custom designed with a polarization bandwidth and position across a wide range of wavelengths. Further still, the light source of this invention is made from low cost materials and is easily manufactured. Yet further still, this invention enables the production of ultra-thin and lightweight polarized light sources.

Polarized light sources and methods for making the same

The present invention includes a polarization independent optical interconnect device for selectively interconnecting a plurality of optical signals between a plurality of inputs and a plurality of outputs. The present invention may provide advantages typically associated with conventional polarization based switches, including terabit per second data rates and high speed switching, to facilitate use in fiber optic networks. Moreover, the switch of this invention is polarization independent, and therefore, may route either polarized or unpolarized light. Since both the input and output light may be unpolarized, the switch of this invention may have a high light efficiency (i.e. no losses associated with an input polarizer) and minimal insertion losses as compared to typical polarization based switches.

Polarization independent non-blocking all-optical switching device

A polarizing plate,is disposed to polarize light parallel to the X axis of liquid crystal display,, which may be optionally rotated to a position where the intensity of a light that transmits the liquid crystal display,takes an extreme value (maximum or minimum) and an output Ix using a photodetector,is measured. The polarizing plate,is then disposed to polarize light parallel to the Y axis to thereby measure an output Iy using the photodetector,. The polarizing plate,is then disposed to polarize the light in the direction inclined by 45 degrees between the X and Y axes to thereby measure an output I,using the photodetector,. A quarter wavelength plate,optionally may be disposed between the polarizing plate,and the liquid display,such that its axial direction is inclined by 45 degrees from the polarizing direction of the polarizing plate,while disposing the polarizing plate,so as to polarize light at 45 degrees from both the X and Y axes. In this position, an output Iq,is measured by the photodetector. Stokes parameters are calculated according to each of the measured values Ix, Iy, I,and Iq,, and according to the calculated Stokes parameters, the thickness of the liquid crystal layer and/or the twist angle of liquid crystal molecules of the liquid crystal display,can be determined. Optionally, the light intensities may be measured by a two-dimensional photodetector and Stokes parameters for a plurality of points on the liquid crystal display may be simultaneously or substantially simultaneously determined.

Methods and apparatus for detecting liquid crystal display parameters using stokes parameters

A method of determining a parameter of a liquid crystal cell is provided in which parameters, such as the thickness of the liquid crystal layer and the angle of the twist of liquid crystal molecule orientation in the liquid crystal cell, are accurately determined in a short time with a simple apparatus. Light from a light source 1 is transmitted through a polarizing plate 2 and incident to a liquid crystal cell 3. The light is transmitted by a polarizing plate 4 and the intensity of the transmitted light is measured by a photodetector 6. Then, the outputs of the photodetector 6 for the following cases are measured: when the polarization direction of the polarizing plate 4 is set (1) in the direction of the X axis, (2) in the direction of Y axis and (3) at 45 degrees to the X and Y axes and (4) when, with the polarization direction of the polarizing plate 4 being at 45 degrees to the X and Y axes, a quarter wavelength plate 5 is inserted between the polarizing plate 4 and the liquid crystal cell 3 so that its axial direction is tilted at 45 degrees to the polarization direction of the polarizing plate 4. Stokes parameters are obtained from the measurement values, and the thickness of the liquid crystal layer and the angle of twist of liquid crystal molecule orientation are calculated from the measured Stokes parameters.

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Bedford Hills, NY, United States of America

Zhan He