Abstract: The present invention provides a diffusely-reflecting polarizer comprising: a first polymer which is amorphous and having a birefringence of less than about 0.02 and a second polymer, the first polymer being a continuous phase, and the second polymer being a disperse phase whose index of refraction differs from said continuous phase by greater than about 0.05 along a first axis and by less than about 0.05 along a second axis orthogonal to said first axis; wherein the diffuse-reflectivity of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%, the diffuse transmittance of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%.

Abstract: The present invention provides a light guide plate comprising: (a) an input surface for receiving light from a light source into the light guide plate, (b) an output surface for emitting light, (c) a bottom surface opposing to the output surface, wherein discrete elements are located at least one of the output or bottom surface, the density function D(x) of the discrete elements has a minimal value Dmin(xmin) for 0.0<xmin<0.25 and a value D0(x0) for x0<xmin and satisfies: D0/Dmin?1>20%.

Abstract: A bistable display having one or more permanent hideable mark, and a method of forming the permanent hideable mark, are described. The permanent hideable mark can be hidden and revealed numerous times without loss of information.

Abstract: The present invention provides a light redirecting article for redirecting light toward a target angle, the light redirecting article comprising: an input surface comprising a plurality of light redirecting structures. Each light redirecting structure has (i) a near surface having two slopes, sloping away from normal in one direction as defined by a first inclination base angle ?1, a second inclination angle ?2, and a first half apex angle ?2, for accepting incident illumination over a range of incident angles and (ii) a far surface sloping away from normal, in the opposite direction relative to the input surface, as defined by a second base angle ?1 and a second half apex angle ?1. In addition, light redirecting structures has (b) an output surface opposing to the input surface, wherein the near and far surfaces are opposed to each other at an angle (?1+?2), and the base angle ?1 is greater than or equal to 90 degrees.

Abstract: The present invention provides a diffusely-reflecting polarizer comprising: a first polymer which is amorphous and having a birefringence of less than about 0.02 and a second polymer, the first polymer being a continuous phase, and the second polymer being a disperse phase whose index of refraction differs from said continuous phase by greater than about 0.05 along a first axis and by less than about 0.05 along a second axis orthogonal to said first axis; wherein the diffuse-reflectivity of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%, the diffuse transmittance of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%.

Abstract: A light redirecting article redirects light toward a target angle. The light redirecting article is made from a material having a refractive index greater than 1.6. The light redirecting article has an input surface for accepting incident illumination over a range of incident angles and an output surface with a plurality of light redirecting structures, each light redirecting structure having a near surface and an exit surface for emitting an output light at an emitted light angle, wherein the exit surface is at an oblique angle relative to the plane of the input surface. For incident illumination at either of at least two different principal angles, each principal angle being greater than 60 degrees from normal and the principal angles having a difference of 5 degrees or greater, the emitted light angle is within 5 degrees of the target angle.

Abstract: A backlight unit comprises: (1) a light source; (2) a light guide plate (LGP) having an incident face toward the light source and having a refractive index nLGP; (3) a reflective polarizer having formed birefringence in optical contact with the LGP including a layer having parameters of the reflective polarizer selected to provide R0>0.8 for one polarization state and T90>0.8 for the orthogonal polarization state, for light of wavelength of 550 nm, for least one reflective polarizer angle of light incidence ?a.

Abstract: A camera apparatus (10) has a zoom lens (12) having a zoom focus setting that is adjustable over a range of focus values and control circuitry for generating a variable voltage potential according to the zoom focus setting. A flash illumination apparatus (20) has a light source (32) and a variable focus liquid crystal lens (24), the variable focus liquid crystal lens (24) having a first and a second solid optical element (40, 50), chamber (44), the two electrodes (42, 48) and liquid crystal material (46). A variable voltage is applied to the liquid crystal material (46) for the lens power according to the zoom focus setting.

Abstract: The present invention provides a diffusely-reflecting polarizer having a first polymer which is amorphous and having a birefringence of less than about 0.02 and a second polymer, the first polymer being a continuous phase, and the second polymer being a disperse phase whose index of refraction differs from said continuous phase by greater than about 0.05 along a first axis and by less than about 0.05 along a second axis orthogonal to said first axis; wherein the diffuse-reflectivity of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%, the diffuse transmittance of said first and second polymers taken together along at least one axis for at least one polarization state of electromagnetic radiation is at least about 50%.

Abstract: A watermark formed of a bistable material, and a method of forming the watermark, are described.

Abstract: A backlight device for a display comprising (1) a side-lit light source, (2) a light guide plate and (3) a turning film comprising a light entry and a light exit surface comprising lenticular elements on the exit surface and prismatic structures on the entry surface, wherein the average values of the parameters of the features and the thickness of the film are selected to provide a peak output angle of ±10° from normal to the light exit surface of the light guide plate and an optical gain of at least 1.25. Also disclosed are methods of making the turning film and a display incorporating the backlight.

Abstract: A display system includes a display arranged to receive an image wise pattern of light to form an image, including, a pair of conductors, at least one conductor being transparent, a layer of cholesteric liquid crystal material disposed between the conductors, the liquid crystal material having multiple stable optical states at zero electrical field, and a light absorber for forming an image wise thermal pattern in the liquid crystal sufficient to change the optical state of the cholesteric liquid crystal in response to an image wise pattern of light; a display writer, including, a light source for producing a flash of light of sufficient intensity to generate sufficient heat in the light absorber to change the optical state of the cholesteric liquid crystal, a mask located between the light source and the display for defining the image wise pattern of light, a display drive connectable to the conductors for generating an electric field between the conductors for changing the optical state of the cholesteric l

Abstract: A method of writing an image on a liquid crystal display of the type having a layer of cholesteric liquid crystal material disposed between a pair of unpatterned conductors and a light absorbing layer for forming an image wise thermal pattern in response to an image wise pattern of light, including applying a first voltage to the conductors; applying a second voltage different from the first voltage to the conductors after applying the first voltage, wherein the first and second voltages are non-zero; and exposing the liquid crystal display to the image wise pattern of light.

Abstract: The present invention provides a light redirecting article for redirecting light toward a target angle, the light redirecting article comprising: an input surface comprising a plurality of light redirecting structures each light redirecting structure having a near surface having two slopes, sloping away from normal in one direction as defined by a first inclination base angle ?1, a second inclination angle ?2, and a first half apex angle ?2, for accepting incident illumination over a range of incident angles and a far surface sloping away from normal, in the opposite direction relative to the input surface, as defined by a second base angle ?1 and a second half apex angle ?1. The invention further provides an output surface opposing to the input surface wherein the near and far surfaces are opposed to each other at an angle (?1+?2) that is in the range from 60 to 70 degrees, and the base angle ?1 is in the range from 82 to 87 degrees.

Abstract: A light redirecting article for redirecting light toward comprises: a light exit surface with features meeting certain requirements; wherein first and second surfaces of the features are opposed to each other at an angle ? that is in the range from 35 to 55 degrees; wherein the light redirecting article is formed from a material having an index of refraction less than 1.60; and wherein the target angle is from 5 to 25 degrees.

Abstract: The invention relates to an optical element including a substrate, a wire grid on one side of said substrate, and prismatic light collimating features on the other side of said substrate

Abstract: A backlight unit comprises: (1) a light source; (2) a light guide plate (LGP) having an incident face toward the light source and having a refractive index nLGP; (3) a reflective polarizer having formed birefringence in optical contact with the LGP including a layer having parameters of the reflective polarizer selected to provide R0>0.8 for one polarization state and T90>0.8 for the orthogonal polarization state, for light of wavelength of 550 nm, for least one reflective polarizer angle of light incidence ?a.

Abstract: A backlight device for a display comprising (1) a side-lit light source, (2) a light guide plate and (3) a turning film comprising a light entry and a light exit surface comprising lenticular elements on the exit surface and prismatic structures on the entry surface, wherein the average values of the parameters of the features and the thickness of the film are selected to provide a peak output angle of ±10° from normal to the light exit surface of the light guide plate and an optical gain of at least 1.25. Also disclosed are methods of making the turning film and a display incorporating the backlight.

Abstract: A camera apparatus (10) has a zoom lens (12) having a zoom focus setting that is adjustable over a range of focus values and control circuitry for generating a variable voltage potential according to the zoom focus setting. A flash illumination apparatus (20) has a light source (32) and a variable focus liquid crystal lens (24), the variable focus liquid crystal lens (24) having a first and a second solid optical element (40, 50), chamber (44), the two electrodes (42, 48) and liquid crystal material (46). A variable voltage is applied to the liquid crystal material (46) for the lens power according to the zoom focus setting.

Abstract: A method of driving an active matrix cholesteric liquid crystal display that includes a matrix of data and select lines and an array of pixels connected to the data and select lines through active switching elements, a pixel being capable of producing two or more gray levels includes providing a select voltage and a plurality of data voltages, and during a pixel writing cycle, applying the select voltage and the data voltages to the select and data lines of the display to produce only three pixel voltage levels 0, +U and ?U, having respective duty cycles and controlling the duty cycles of the pixel voltage levels to determine the gray levels of the pixels, and wherein the average voltage applied to a pixel during the pixel writing cycle is zero.