Abstract: A welding helmet and lens therefor includes a shield and a lens including a two identical optical components, each including a polarizer, a further polarizer (analyzer) optically between said optical components and effectively shared as an output device from one optical component and an input device for the other optical component, the transmissive axes of respective polarizers of said optical components being operatively oriented relative to one another to improve extinction of light incident on said lens at prescribed angles. The lens may be used in other optical systems.

Abstract: A polarizer including liquid crystal material and a surface or surfaces for cooperating with the liquid crystal material to control polarization of light which is incident in a direction normal to the polarizer by at least one of refraction and total internal reflection of one polarization component of the light while transmitting the other polarization component substantially in the direction without refraction or total internal reflection, the surface or surfaces including plural grooves in cooperative relationship with the liquid crystal material.

Abstract: A method of making a liquid crystal polarizer includes casting an emulsion of liquid crystal material with pleochroic dye in a containment medium, and forming elongate volumes of said liquid crystal material and pleochroic dye in said containment medium. A liquid crystal polarizer device includes liquid crystal material having low birefringence, a containment medium for containing said liquid crystal material in elongate volumes, and means in combination with said liquid crystal material for affecting polarization of light incident thereon; the liquid crystal material being responsive to a prescribed input to change the optical polarization characteristic of the device.

Abstract: Apparatus for filtering a wavelength of light includes a variable polarization rotator for supplying linearly polarized input light at a prescribed angle of polarization, a cholesteric liquid crystal variable dispersion device for rotating the plane of polarization of the plane polarized light from the variable polarization rotator an amount that is a function of the wavelength of such input light, and analyzer for blocking transmission of that light which is output by said variable dispersion device and has a plane of polarization which is crossed relative to the axis of polarization of the analyzer, while transmitting at least part of the light which does is not plane polarized in a direction that is crossed relative to the analyzer.

Abstract: Apparatus for rotating polarization of polarized light includes an input of linearly polarized light, a variable retarder for retarding the phase of one quadrature component of such linearly polarized input light an amount relative to the phase of the other quadrature component, and an analyzer for converting such quadrature components to linearly polarized light having a plane of polarization that is a function of the amount of such phase retardation. By changing the electrical input to the retarder the amount of rotation can be altered.

Abstract: A liquid crystal color device (10) includes at least one pel (14) for affecting light (36) incident thereon to produce output light (38), the pel includes three complementary color subsets (30, 32, 34), each having controllable color filtering capability in the respective complementary colors thereof. The color subsets are arranged in optical additive relation, and the color subsets include complementary color parts (30a, 30b, 32a, 32b, 34a, 34b) which are arranged, respectively, in optical serial/subtractive relation. The color filtering function is carried out using liquid crystal materials with respective pleochroic dyes. A method of parametric color control of a liquid crystal device, formed of plural picture elements, each picture element including plural pairs of complementary color filters, comprising directing light to or through an array of such electrically controllable pairs of complementary color filters, and controlling the filtering characteristics of at least one of such filters.

Abstract: A system for protecting the eyes of a wearer while permitting information to be conveyed to such eyes includes a first plane polarizer for selectively passing incident light or other electromagnetic energy toward such eyes as a function of a prescribed characteristic, such as polarization direction of such electromagnetic energy, a second plane polarizer for selectively passing incident light (electromagnetic energy) passed by the first polarizer toward such eyes as a function of a prescribed characteristic, such as polarization direction, of such electromagnetic energy, a means for changing such characteristic (i.e.

Abstract: An optical read/write information storage system (2), includes a liquid crystal information storage medium (1) for storing information written thereto and being capable of being read, including plural volumes (21) of liquid crystal material (23) in a containment medium (24), the volumes of liquid crystal material being operative to modulate or not to modulate light, e.g. by transmitting or scattering light as a representation of logic 1 and logic 0 information, the storage medium being responsive to a first energy input to assume and to store one detectable output condition and to a second energy input to assume and to store a second detectable output condition, input energy systems for writing and erasing information, and an optical reading device for detecting such output conditions of the storage means as a representation of information stored therein. Pleochroic dye (250) may be used to enhance thermal effects.

Abstract: Briefly, according to one aspect of the invention, liquid crystal material having a smectic phase is encapsulated; and according to further aspects there are provided methods for encapsulating liquid crystal material having a smectic phase and for making a liquid crystal device using such encapsulated liquid crystal material.

Abstract: A liquid crystal color display (20) provides a transmitted light output of one or more colors, black, and/or white, as a function of incident light and controlled energization or not of respective optically serially positioned liquid crystal color layers (2, 3, 4) and/or multicolor composite liquid crystal color layer(s) in the display. Plural optically serially arranged volumes (21) of operationally nematic liquid crystal material (25) having different optical characteristics, e.g. being dyed with different pleochroic dyes (28), may be selectively aligned or not with respect to an electric field to determine optical output of the device in a subtractive color mode. Exemplary colors of pleochroic dye include yellow, cyan and magenta, and black dye may be used to control saturation or hue. Non-pleochroic dye also may be used in one or more layers of the liquid crystal color display to filter or to color light transmitted therethrough thereby to cooperate with the pleochroic dye to provide a final color output.

Abstract: Light transmission control device includes band pass filter for transmitting light of a wavelength or group of wavelengths and partially blocking transmission of light of a different wavelength or group of wavelengths, and variable optical filter for controllably transmitting light of a wavelength or group of wavelengths, the band pass filter and variable optical filter being cooperative to provide at least three light transmitting modes, including maximum transmission, minimum transmission, and a third mode less transmissive than the maximum, the device being operative to minimum transmissive mode upon being driven by a maximum energy input, the device also being operative to maximum transmissive mode upon being driven by a lesser energy input, and such third transmission mode occurring in response to no power or a failure of power or adequate power for energizing the device to the maximum or minimum transmissive mode.

Abstract: A liquid crystal color display provides a transmitted light output that is of one or more colors, black, and/or white, as a function of the color of the incident light input and controlled energization or not of respective optically serially positioned liquid crystal color layers and/or multicolor composite liquid crystal color layer(s) in the display. In one case, the display includes a plurality of liquid crystal color layers, each being dyed a different respective color, and apparatus for selectively applying a prescribed input, such as an electric field of a given voltage level or frequency, to a respective layer or layers or to a portion or portions thereof. Each liquid crystal layer includes plural volumes of operationally nematic liquid crystal material in a containment medium that tends to cause an alignment of the liquid crystal structure and, thus, pleochroic dye included or mixed with the liquid crystal material in each layer to absorb light.

Abstract: An apparatus for responding to incident electromagnetic radiation includes a first medium having a surface and through which incident electromagnetic radiation may be transmitted, a second such medium having a surface, the surfaces being generally parallel, and smectic liquid crystal between said surfaces and aligned generally in parallel in layers that extend generally parallel to each other and perpendicularly to such surfaces (bookshelf alignment), the liquid crystal material being operative to undergo self-focusing in response to a characteristic of incident electromagnetic radiation exceeding a value and being cooperative with at least one of such media thereby automatically to limit the energy or energy density of electromagnetic radiation exiting the apparatus.

Abstract: A liquid crystal color display provides a transmitted light output that is of one or more colors, black and/or white, as a function of the color of the incident light input and controlled energization or not of respective optically serially positioned liquid crystal color layers and/or multicolor composite liquid crystal color layer(s) in the display. Each liquid crystal layer may include plural volumes of operationally nematic liquid crystal material in a containment medium that tends to distort the natural liquid crystal structure in the absence of a prescribed input. Each layer includes a dye mixed with the liquid crystal material so as to have a particular coloring effect on light incident thereon. By selectively energizing or not respective portions of respective liquid crystal color layers, a multi-color light output can be produced. Such light output may be employed in a liquid crystal display that produces stationary or moving images.

Abstract: A liquid crystal color display (20) provides a transmitted light output of one or more colors, black, and/or white, as a function of incident light and controlled energization or not of respective optically serially positioned liquid crystal color layers (2, 3, 4) and/or multicolor composite liquid crystal layer(s) in the display. Plural optically serially arranged volumes (21) of operationally nematic liquid crystal material (25) having different optical characteristics, e.g. being dyed with different pleochroic dyes (28), may be selectively aligned or not with respect to an electric field to determine optical output of the device in a subtractive color mode. Exemplary colors of pleochroic dye include yellow, cyan and magenta, and black dye may be used to control saturation or hue. Non-pleochroic dye also may be used in one or more layers of the liquid crystal color display to filter or to color light transmitted therethrough thereby to cooperate with the pleochroic dye to provide a final color output.

Abstract: Liquid crystal temperature indicating compositions, preferably absent cholesteric liquid crystal material, and the containing of such compositions in volumes formed in a containment medium (29) that tends to distort the liquid crystal structure (36) when the temperature thereof is below a transition or clearing point temperature (FIG. 4). The containment medium (29) is water resistant, e.g. insoluble in water, and preferably has heat and optical stability, e.g., does not brown or otherwise discolor, at relatively high temperatures, e.g. above 100.degree. C. Plural liquid crystal materials having different transition temperatures may be mixed to form a liquid crystal material having a transition temperature intermediate those of the ingredients (FIG. 11).

Abstract: According to one aspect of the invention, a system for controlling light, includes (1) apparatus for responding to incident electromagnetic radiation, including a first medium through which incident electromagnetic radiation may be transmitted; liquid crystal means positioned with respect to said first medium for responding to a characteristic of the incident electromagnetic radiation to cooperate with such first medium to effect refraction of such electromagnetic radiation at an interface of said first medium and said liquid crystal means; and (2) apparatus for filtering a wavelength of light, including a variable polarization rotator means for supplying input light at a prescribed angle of polarization, variable dispersion means for rotating the plane of polarization of such input light an amount that is a function of the wavelength of such input light, and analyzer means for blocking transmission of that light which is output by said variable dispersion means and has a plane of polarization which is crosse

Abstract: A variable density light control apparatus includes plural polarizers, at least two of which are at least partially crossed, and at least one of the polarizers being variable to the extent that it polarizes light as a function of a prescribed input, thereby to control the intensity of light transmitted through the apparatus proportionally to the intensity of the incident light to the apparatus. The range of intensity control can be varied according to the crossed relationship of the polarizers and/or according to the polarization effectiveness of the controllable polarizer. Color effects can be controlled. The apparatus may be utilized in various devices, including displays, windows, eye glasses, and ski goggles.

Abstract: A liquid crystal color display provides a transmitted light output that is of one or more colors, black, and/or white, as a function of the color of the incident light input and controlled energization or not of respective optically serially positioned liquid crystal color layers and/or multicolor composite liquid crystal color layer(s) in the display. In one case, the display includes a plurality of liquid crystal color layers, each being dyed a different respective color, and apparatus for selectively applying a prescribed input, such as an electric field of a given voltage level or frequency, to a respective layer or layers or to a portion or portions thereof. Each liquid crystal layer includes plural volumes of operationally nematic liquid crystal material in a containment medium that tends to cause an alignment of the liquid crystal structure and, thus, pleochroic dye included or mixed with the liquid crystal material in each layer to absorb light.

Abstract: A liquid crystal apparatus comprising a nematic curvilinearly aligned phases liquid crystal material located between two electrodes wherein a control element is incorporated into the electrodes. The electrodes may also form a circuit means integral therewith for selectively applying an electric field across the liquid crystal material.