Abstract: The current invention relates to a patterned optical device comprises a patterned cholesteric liquid crystal polymer layer where different domains of the pattern reflect different colors and where luminescent molecules are embedded in a subset of said reflective domains or in a separate layer. The current invention also relates to an optical security device comprises overt reflective OVD images and covert luminescent images with multiple authentication levels including detection of polarized reflections and emissions.

Abstract: Disclosed herein is a transmissive or reflective optical security device, containing a hidden image, that is based on patterned retardation in a single layer of a nematic liquid crystal polymer on a substrate and methods of fabricating said hidden image by selectively modifying the retardation value. Fabrication methods that are compatible with high throughput standard roll-to-roll or printing lines are disclosed. Said image becomes visible under polarized illumination. The hidden image feature enhances the counterfeiting resistance of the security device.

Abstract: The current invention relates to methods for generating images with multiple reflection colors in a single layer of cholesteric liquid crystal polymer (CLCP) for optical security applications such as optical devices and labels for brand protection or document security. The multicolor feature enhances the counterfeiting resistance of a CLCP based optical devices, in addition to its intrinsic polarized selective reflection and being an optical variable device. The fabrication methods include: digital printing on CLCP, the use of heat transfer masks and UV masks as well as hot stamping techniques. Embodiments are presented that adapt the above methods to continuous, roll-to-roll printing lines.

Abstract: The present invention relates generally to an optical security device and an optical security system in which hidden images that are invisible to the naked eye under unpolarized illumination, become visible under either linearly or circularly polarized illumination. Preferred fabrication methods of said optical security device are disclosed.

Abstract: The present invention relates generally to an optical security device and an optical security system in which hidden images that are invisible to the naked eye under unpolarized illumination, become visible under either linearly or circularly polarized illumination. Preferred fabrication methods of said optical security device are disclosed.

Abstract: Methods of applying covert features using security inks comprise transparent chiral birefringent pigments or a mixture of transparent chiral birefringent pigments and reflective pigments are described. Hidden features appear to be bright and achromatic against dark background when overlaid with circular polarizer.

Abstract: An image display system includes a polarized image projection device, a polarization preserving transmissive diffusiver, and a polarizing reflector element as a non-blocking mirror (referred to as a “combiner”). The combination of a polarization preserving transmissive diffuser or rear projection screen and a polarizing reflector results in a high brightness HUD for applications including automotive, aerospace, or other applications where HUD systems are used. The system also maintains the low haze and high transmittance of the windshield that will meet the requirement of standards of windshields for motor vehicles and similar applications.

Abstract: A display system in which images from two displays that have the same optical polarization that is not affected by reflection by a beam splitter which combines images from the displays, and a half wave plate optical retarder to rotate plane of polarization of light from one display prior to impingement on the beam splitter, and a polarizer filter to block transmission to the beam splitter of leakage light caused by optical dispersion by the half wave plate. A display system in which images represented by polarized light from two displays are incident on a DBEF beam splitter, the direction of plane of polarization of one of the images relative to the DBEF is such that the DBEF preferentially transmits that direction and the direction of plane of polarization of the other of the images, which is directed to the other surface of the beam splitter, is such that the DBEF preferentially reflects that light.

Abstract: A backlight for a liquid crystal display (LCD) employing light recycling. In one embodiment the backlight includes a light guide fabricated from a substantially non-absorptive material and a reflective layer fabricated from a highly reflective material. In another embodiment the backlight includes a light source, a bundle of optical fibers, and a reflective layer fabricated from a highly reflective material, wherein the bundle of optical fibers is configured to receive light from the light source and distribute it to the reflective layer.

Abstract: A reflective liquid crystal display (LCD) including a cholesteric liquid crystal polarizing device and a liquid crystal cell superimposed with one another. In various embodiments, the reflective LCD may be a normally white mode or normally black mode device. In another variation, the liquid crystal cell may include a 90° twisted nematic liquid crystal.

Abstract: A color liquid crystal display using reflective color filters using layers of cholesteric liquid crystals is disclosed. The reflective color filters have two different center wavelengths and bandwidths per layer and are stacked in two layers to provide colored light for displays. With various numbers of layers in the stack, different polarization levels are provided. The pixels in the display of the invention are arranged such that multiple adjacent sub-pixels in a layer with the same color makes the color filters easier to manufacture.

Abstract: A backlight for a liquid crystal display (LCD) employing light recycling. In one embodiment the backlight includes a light guide fabricated from a substantially non-absorptive material and a reflective layer fabricated from a highly reflective material. In another embodiment the backlight includes a light source, a bundle of optical fibers, and a reflective layer fabricated from a highly reflective material, wherein the bundle of optical fibers is configured to receive light from the light source and distribute it to the reflective layer.

Abstract: A color liquid crystal display using reflective color filters using layers of cholesteric liquid crystals is disclosed. The reflective color filters have two different center wavelengths and bandwidths per layer and are stacked in two layers to provide colored light for displays. With various numbers of layers in the stack, different polarization levels are provided. The pixels in the display of the invention are arranged such that multiple adjacent sub-pixels in a layer with the same color makes the color filters easier to manufacture.

Abstract: An image display system includes a polarized image projection device, a polarization preserving transmissive diffusiver, and a polarizing reflector element as a non-blocking mirror (referred to as a “combiner”). The combination of a polarization preserving transmissive diffuser or rear projection screen and a polarizing reflector results in a high brightness HUD for applications including automotive, aerospace, or other applications where HUD systems are used. The system also maintains the low haze and high transmittance of the windshield that will meet the requirement of standards of windshields for motor vehicles and similar applications.

Abstract: Reflective color filters using layers of cholesteric liquid crystals with two different center wavelengths and bandwidths per layer are stacked in two layers to provide colored light for displays. With a two layer stack circularly polarized light of one handedness can be provided. With a two layer stack circulary unpolarized colored light can be provided. With a broadband polarizing filter overlapping other filters in the stack a black matrix can be provided by reflecting all colors and transmitting no light in the overlapping areas. When broadband reflective cholesteric liquid crystals are used two primary colors can be reflected in the same pixel of a display making reflective layers with two reflective portions per layer possible. Color displays having three linear sub-pixels with three primary colors or with four sub-pixels of white, blue, green, and red in a pixel with two colors in a top row and two colors on a bottom row can are made with two colors per layer in two layer stacks.

Abstract: Reflective color filters using layers of cholesteric liquid crystals with two different center wavelengths and bandwidths per layer are stacked in two layers to provide colored light for displays. With a two layer stack circularly polarized light of one handedness can be provided. With a four layer stack unpolarized colored light can be provided. With a broadband polarizing filter overlapping other filters in the stack a black matrix can be provided by reflecting all colors and transmitting no light in the overlapping areas. When broadband reflective cholesteric liquid crystals are used two primary colors can be reflected in the same pixel of a display making reflective layers with two reflective portions per layer possible. Color displays having three linear sub-pixels with three primary colors or with four sub-pixels of white, blue, green, and red in a pixel with two colors in a top row and two colors on a bottom row can are made with two colors per layer in two layer stacks.

Abstract: A cholesteric liquid crystal polarizing device includes a substrate, an alignment layer, and a cholesteric liquid crystal layer including multiple domains, each of said domains skewed at an angle relative to a plane parallel to said substrate. The device may be used in combination with a liquid crystal cell to fabricate a reflective liquid crystal display (LCD). In various embodiments, the reflective LCD may be a normally white mode or normally black mode device. In another variation, the liquid crystal cell may include a 90° twisted nematic liquid crystal.

Abstract: A backlight for a liquid crystal display (LCD) employing light recycling. In one embodiment the backlight includes a light guide fabricated from a substantially non-absorptive material and a reflective layer fabricated from a highly reflective material. In another embodiment the backlight includes a light source, a bundle of optical fibers, and a reflective layer fabricated from a highly reflective material, wherein the bundle of optical fibers is configured to receive light from the light source and distribute it to the reflective layer.

Abstract: A reflective liquid crystal display (LCD) including a cholesteric liquid crystal polarizing device and a liquid crystal cell superimposed with one another. In various embodiments, the reflective LCD may be a normally white mode or normally black mode device. In another variation, the liquid crystal cell may include a 90° twisted nematic liquid crystal.

Abstract: A laser-addressable liquid crystal cell includes first and second transparent substrate layers forming the outer surfaces for the cell. First and second electrode layers are each formed from a transparent electrically conductive material, with the first and second electrode layers adjacent the first and second substrate layers, respectively. A smectic liquid crystal layer is disposed between the electrode layers. A three layer structure is disposed between the liquid crystal layer and the second electrode layer for absorbing infrared radiation while permitting visible radiation to pass therethrough. This structure includes a layer of radiation absorbing material, a layer selectively reflective to infrared radiation and transparent to visible radiation, and a spacer layer of dielectric material disposed therebetween.