Abstract:
The range of spatial frequencies of the information areas in an optical record carrier (130) that can be read by conventional means can be increased substantially by providing the information layer (1134) with a birefringent diffraction grating (136) and using a read beam (b) that comprises two mutually perpendicular polarised components (b1, b2) only one of which will be diffracted by the grating.
Abstract:
The invention relates to a method for manufacturing a diffusive reflector (450) for a reflective or transflective Liquid Crystal Display (400). The reflector comprises a surface (452) that is structured by means of a photo-embossing process. Herein, a layer (100) of a mixture is provided including a photo-diffusible monomer (102), which may be transported through the layer under the influence of selectively applied irradiation. A layer relief is thus formed, which is preferably developed further at an elevated temperature. The layer is fixed and stabilized by means of a cross-linking step, preferably including thermally induced and/or photo-induced polymerization. In a final step, the polymer relieved surface thus formed is provided with a reflective material (154).
Abstract:
A polarizing arrangement comprises a first linear polarizer having a first extinction axis. The polarization contrast ratio of the first polarizer is dependent on the angle a light beam incident on the polarizer makes with the extinction axis, polarization being most efficient when the light beam is orthogonal to the first extinction axis. In order to improve the polarization contrast ratio, for light beams traveling in directions which make an angle with the first extinction axis of the first polarizer the polarizing arrangement comprises a second polarizer having a second extinction axis. The first and second polarizer are arranged relative to one another such that, in operation, a light beam traversing the first polarizer in a direction orthogonal to the first extinction axis traverses the second polarizer in a direction coincident with the second extinction axis. The second polarizer has a similar angular-dependent polarization contrast ratio which due the specific arrangement of the first extinction axis with respect to the second extinction axis compensates the reduction of polarization contrast ratio for the first polarizer for light beams which make an angle with the first extinction axis.
Abstract:
Display apparatus comprising an image-generating screen (46) repetitively scanned at a predetermined rate to display images, and a backlight for illuminating the screen. The backlight includes a light guide (10) arranged to constrain light by total internal reflection, the light guide having an output surface (22) with various locations from which light may be selectively coupled using a scanning arrangement (44). The scanning arrangement sequentially and repeatedly illuminates selected areas of said screen in synchronism with the repetitive scanning of the screen.
Abstract:
Optical data storage method, device and storage medium, comprising storing data by modifying optical properties of polymer material, whereby writing is initiated by reorientation of photoorientable units, typically by illuminating with light at a wave-length that initiates the reorientation.
Abstract:
The invention relates to a photo-embossing process for the preparation of a polymeric relief structure comprising the steps of: a) coating a substrate with a coating composition comprising one or more radiation-sensitive ingredients and less than 30 wt % polymeric binder material; b) locally treating the coated substrate with electromagnetic radiation having a periodic, non-periodic or random radiation-intensity pattern, forming a latent image, at a temperature below a transition temperature of the coating composition; and c) polymerizing and/or crosslinking the resulting coated substrate, at a temperature above said transition temperature, wherein the transition temperature is a temperature that defines a transition of the coating composition between a state of high viscosity and low viscosity and wherein the coating composition comprises a compound A comprising at least one radiation curable group and a photoinitiator, the coating composition having a transition temperature between 30° C. and 120° C.
Abstract:
This invention relates to a display device (1), comprising a display panel (2) having a layer of electro-optical material (4), a first light-transmissive substrate (5) provided with electrodes (7) in an area of pixels arranged in rows and columns, a second light transmissive substrate (6), said layer of electro-optical material (4) being sandwiched between said first and second layer (5, 6), and an illumination system (3), being arranged on a side of the second substrate (6) being remote from said layer of electro-optical material (4), the illumination system comprising an optical waveguide (14) of an optically transparent material, having an exit face (15) facing said display panel (2). According to the invention, the illumination system (3) further comprises a matrix-addressable light-management member (27).
Abstract:
The invention relates to an optically anisotropic body, such as a compensation foil or a micro-lens array, having a desired pattern of optical properties. Said body is obtainable by a method wherein a non-uniform electric and/or magnetic field is applied over a body comprising a polymerizable electro-optical and/or magneto-optical material, such as a LC monomer, thus inducing a desired molecular pattern. The pattern is made permanent by polymerising the electro-optical and/or magnetooptical material.
Abstract:
The invention relates to producing an optical memory which combines stability of written and non-written data with high writing speed and good sensitivity during writing, such an optical memory as well as a method of writing in such a memory. The optical memory has a liquid crystal (LC) layer with a first type of LC molecules (102) aligned in one direction, forming a polymer network (108), and a second type of LC molecules (104) oriented in a perpendicular direction, in which the orientation of said second type of LC molecules is meta-stable. By making use of a force, exerted on the second type of LC molecules (104), by the network of aligned crosslinked molecules, an increase in relaxation rate for the second type of molecules (104) from a meta-stable state of orientation, is achieved, which makes it possible to use said relaxation for writing data at an increased writing rate.
Abstract:
The invention relates to a photo-embossing process for the preparation of a polymeric relief structure comprising the steps of: a) coating a substrate with a coating composition comprising one or more radiation-sensitive ingredients and less than 30 wt % polymeric binder material; b) locally treating the coated substrate with electromagnetic radiation having a periodic, non-periodic or random radiation-intensity pattern, forming a latent image, at a temperature below a transition temperature of the coating composition; and c) polymerizing and/or crosslinking the resulting coated substrate, at a temperature above said transition temperature, wherein the transition temperature is a temperature that defines a transition of the coating composition between a state of high viscosity and low viscosity and wherein the coating composition comprises a compound A comprising at least one radiation curable group and a photoinitiator, the coating composition having a transition temperature between 30° C. and 120° C.