Abstract: The present invention provides organogermanium compounds and liquid crystal compositions comprising such a compound.

Abstract: An optical device includes a ferroelectric liquid crystal material. This optical device has a first and a second substrate. A first alignment treatment is applied to a surface of the first substrate, the first alignment treatment being intended to induce an orientation of at least a portion of the ferroelectric liquid crystal material along a first alignment direction with a first pretilt angle ?1 with respect to a plane parallel to the first substrate. A second alignment treatment is applied to a surface of the second substrate, the second alignment treatment being intended to induce an orientation of at least another portion of the ferroelectric liquid crystal material along a second alignment direction with a second pretilt angle ?2 with respect to a plane parallel to the second substrate.

Abstract: A microdisplay having interface circuitry on the same silicon backplane to allow it to receive digital images and video in a variety of formats and convert same to field sequential color signals for generation of full color images. It includes column data processors having a comparator for each block of N-columns of pixels. Image data is double-buffered in SRAM memory cells located beneath the pixel electrodes, but not within each pixel. The stored data is logically associated with each pixel via the column data processors. Image compression is accomplished by converting RGB data to a variant of YUV data and sampling the color components of the converted data less frequently than the luminance components. The SRAM image buffer consumes a reduced amount of power. A temperature compensation scheme allows the temperature of the microdisplay to be sensed and the drive voltage to the pixel electrodes to be varied in response thereto.

Abstract: An electronic viewfinder with a reflective microdisplay and associated optical elements in a design that utilizes one or more folded optical paths to achieve a compact size and volume that may have a dimension of less than 10 millimeters per side. Moreover, the optical design may have an effective focal length that is greater than the spacing of the optical elements from the microdisplay. Various embodiments include a pancake window arrangement with reflective surfaces that are spaced apart from each other and cube beamsplitter eyepieces with folded paths.

Abstract: The invention relates to chiral nonracemic liquid crystal compounds having achiral tails comprising a perfluoroalkyl terminal portion which are useful as components in liquid crystal to impart high polarization to the mixture. The materials of this invention can be combined with known liquid crystal host materials to impart improved properties. Chiral nonracemic compounds of this invention can function as additives or dopants in host materials to impart chirality into an LC material.

Abstract: A system for producing spatially modulated monochrome or color light having gray scale includes an active matrix liquid crystal spatial light modulator having light modulating means including (i) a layer of ferroelectric liquid crystal material which is designed to switch between ON and OFF states and (ii) active matrix means including VLSI circuitry for dividing the layer of liquid crystal material into an array of individual liquid crystal pixels and for causing each of the pixels of liquid crystal material to modulate light individually by switching between the ON and OFF states in a way that depends upon the data which the VLSI circuitry is written. The system also includes illumination means having a light source for directing light from the source into the pixel-divided layer of ferroelectric liquid crystal material in a specific way.

Abstract: A technique for providing a desired level of color balance in field sequential color systems with brightness enhancement. In color wheels having a spectrally-broad transmissive segment, the spectrally-broad segment has a transmittance that is selected to provide a desired level of color balance. This can include transmittance characteristics that are inversely related to the spectral characteristics of the light source or optics. In color switches, this can include varying the amplitude and time duration of the contribution from each of the three primary colors.

Abstract: A display system includes a display panel having an array of pixels, the pixels having ON states and OFF states. The pixels form images by modulating light in a temporal sequence during an image frame in response to drive signals generated from incoming video data. A light source arrangement that emits at least two colors of light illuminates the display panel. The image frame is divided into color segments with only one color of light being emitted from the light source during each segment. The color segments are further divided into grayscale periods. Transition segments are provided for the transitions between colors. The state of each pixel during these transition segments is a function of the desired brightness level for each pixel, as derived from incoming video data.

Abstract: The invention provides LC compositions that exhibit V-shaped switching when aligned in an analog device configuration and exhibit bistability when aligned in a bookshelf-type device configuration. The invention more specifically provides LC compositions of formula 1 and particularly chiral nonracemic compounds of formula 1 which exhibit bistable switching as well as V-shaped switching when aligned in appropriate device configurations. The invention also provides methods of using the compounds of the invention in making LC compositions and electooptical devices comprising an aligned layer of the compositions of this invention.

Abstract: The present invention provides organogermanium compounds and liquid crystal compositions comprising such a compound.

Abstract: A display system includes a display panel having an array of pixels, the pixels having ON states and OFF states. The pixels form images by modulating light in a temporal sequence during an image frame in response to drive signals generated from incoming video data. A light source arrangement that emits at least two colors of light illuminates the display panel. The image frame is divided into color segments with only one color of light being emitted from the light source during each segment. The color segments are further divided into grayscale periods. Transition segments are provided for the transitions between colors. The state of each pixel during these transition segments is a function of the desired brightness level for each pixel, as derived from incoming video data.

Abstract: A system for producing modulated light is disclosed. The system comprises a spatial light modulator including a light modulating medium switchable between different states so as to act on light in ways which form overall patterns of modulated light. The system also includes an arrangement for switching the modulating medium between the different states in a controlled way and an illumination arrangement for producing a source of light. The system further includes an optics arrangement for directing light from the source of light into the spatial light modulator and for directing light from the spatial light modulator through a predetermined source imaging area. The optics arrangement cooperates with the illumination arrangement and the spatial light modulator so as to produce a real image of the source of light within the source imaging area such that an individual is able to view a virtual image of the overall patterns of modulated light from the source imaging area.

Abstract: Bistable and analog FLC devices employing chiral nonracemic liquid crystal materials exhibiting de Vries smectic A phases. The invention provides certain liquid crystal material that can be employed in both bistable and analog device configurations. The invention also provides a method for identifying liquid crystal materials that will exhibit both bookshelf structure in SSFLC cells and provide V-shaped switching in an analog device configuration.

Abstract: The invention relates to chiral nonracemic liquid crystal compounds which are useful as components in liquid crystal compositions to impart high polarization to the mixture. The materials of this invention can be combined with liquid crystal host materials to impart improved properties to mixtures. Chiral nonracemic compounds of this invention can function as additives or dopants in host materials to impart chirality into an LC material.

Abstract: Compounds useful as components of LC and FLC compositions which in turn are useful in the manufacture of optical devices. Compounds of this invention have a silane tail, which can contain more than one Si. Compounds of this invention can include those with disilane tails. The invention provides LC compositions containing one or more of the silanes of this invention. Addition of one or more of the compounds of this invention to LC compositions can result in significant improvement in optical or LC properties. In particular, the compounds of this invention can significantly lower the melting point, freezing point or both of an LC composition resulting in significant improvement in device stability.

Abstract: Compounds that are useful as components in liquid crystal compositions, particularly in ferroelectric liquid crystal compositions. Compounds of the invention are rod-like molecules with a mesogenic (generally linear) core to which an alkene tail and an alkyl or alkoxy tail with a perfluoroalkyl terminal portion are bonded. Compounds of the invention can contain a variety of one, two or three ring cores, wherein the rings maybe aromatic or alicyclic. Alkenes of the invention are useful as components to improve LC properties of mixtures, for example, to lower melting point of lower freezing point, of LC compositions.

Abstract: Chiral nonracemic, chiral racemic and achiral compounds useful as component of LC compositions which have a silane tail group which is partially fluorinated. The silane tail group comprises a perfluoroalkyl group. The silane tail group of this invention has the formula: where k is 0 or an integer ranging from 1-10; m and n are integers ranging from 1 to about 20; j is 0 or an integer ranging from 1 to 20; Z is —O— or a single bond; R1, R1′, R2 and R2′ are alkyl groups or perfluorinated alkyl groups; and RF is a perfluorinated alkyl group. The invention also provides LC compositions comprising one or more compounds of the invention with partially fluorinated silane tails. The invention also provides optical devices, particularly display devices which contain an aligned layer of an LC composition comprising one or more silane compounds of this invention.

Abstract: Liquid crystal materials that exhibit bookshelf structures are provided. When these bookshelf materials are incorporated into a bistable host material, the mixture exhibits a higher switching angle and increased A to C phase transition than bistable hosts without the bookshelf material. These bookshelf materials and bistable compositions are useful in liquid crystal displays, for example.

Abstract: A multi-state light modulating system having grayscale based on a series of time intervals includes an arrangement that establishes the duration of each time interval such that the time intervals in the series have progressively varying duration. The arrangement also determines a drive signal for each time interval that causes the light modulator to assume a specific light modulating state. The arrangement also causes the light modulator to produce a desired time-averaged light level over the series of time intervals by in part driving the light modulator using the drive signal that corresponds to a particular time interval for a duration that is longer than the duration of the time interval. The arrangement also or alternatively arranges the series of time intervals such that the light modulator is in the same state immediately prior to the particular time interval as the light modulator is in immediately after the time interval.

Abstract: A display system includes a light modulator divided into an array of individually controllable pixels and an input-driven illumination device. The illumination device is adapted to receive a variable input and is configured to direct light of variable intensity onto the modulator, depending on the input. The display system further includes a calibrating arrangement for establishing the input to the illumination device to produce a desired intensity level of light. The calibrating arrangement includes a light sensing mechanism, which senses the light from the illumination device while the illumination device is driven by an initial input. The calibration arrangement is configured to determine a comparison between the sensed light and a value representative of the desired-intensity level. The calibration arrangement further includes a control arrangement responsive to the comparison for varying the input so as to provide light of the desired intensity level.