Abstract: A light guide including a light guide body having a light re-directing side positioned opposite from a light output side. A plurality of elongate prisms are located adjacent the light output side of the light guide body. The prisms extend side-by-side relative to one another along lengths. The prisms include upper edges defining heights of the prisms. The upper edges extend along the lengths of the prisms. Each upper edge includes a plurality of edge segments having different magnitudes of slope. The light guide also includes a plurality of light extraction structures located adjacent the light re-directing side of the light guide body for reflecting light toward the light output side. The light extraction structures include elongated projections each having a plateau segment and first and second facets. The elongated projections are separated by lands that are recessed relative to the plateau segments. The first and second facets extend from the plateau segments to the lands.

Abstract: A polarizer construction is disclosed that includes a reflective polarizer disposed on a first side of the construction to transmit light having one polarization and reflect light having an orthogonal polarization, and one or more colored dichroic polarizers disposed on a second side of the construction. The one or more colored dichroic polarizers are arranged so that when the construction is illuminated from the first side, an observer viewing the construction from the second side will observe a first spectral distribution of visible light, and when the construction is illuminated from the second side, an observer viewing the construction from the second side will observe a second spectral distribution of visible light different from the first spectral distribution. Various display constructions using colored polarizers to achieve color changing and image reversal effects are also disclosed.

Abstract: Display apparatuses are shown capable of displaying information in a reflective mode using only ambient light and in a transmissive mode using a light source. In one embodiment, the display apparatus includes a reflecting polarizer disposed between a light modulating layer and an isotropic light cavity. The light cavity reflects incident light with a first degree of depolarization. The reflecting polarizer reflects light with a second degree of depolarization for at least one polarization that is greater than the first degree of depolarization. In another embodiment of the display apparatus, a microstructured film is included above a light cavity and below a light modulating system where the microstructured film includes sawtooth formations having at least a tilted surface.

Abstract: A film that includes a first reflective polarizer substantially reflecting light having a first polarization state and substantially transmitting light having a second polarization state, a polarization rotating layer or depolarizing layer (or both) positioned to receive light passing through the first reflective polarizer, and a second reflective polarizer positioned to receive light passing through the polarization rotating layer or depolarizing layer, the second reflective polarizer substantially reflecting light having a third polarization state back through the polarization rotating layer or depolarizing and substantially transmitting light having a fourth polarization state. Articles containing the film can be formed.

Abstract: A light guide including a light guide body having a light re-directing side positioned opposite from a light output side. A plurality of elongate prisms are located adjacent the light output side of the light guide body. The prisms extend side-by-side relative to one another along lengths. The prisms include upper edges defining heights of the prisms. The upper edges extend along the lengths of the prisms. Each upper edge includes a plurality of edge segments having different magnitudes of slope. The light guide also includes a plurality of light extraction structures located adjacent the light re-directing side of the light guide body for reflecting light toward the light output side. The light extraction structures include elongated projections each having a plateau segment and first and second facets. The elongated projections are separated by lands that are recessed relative to the plateau segments. The first and second facets extend from the plateau segments to the lands.

Abstract: Polarizers are provided that are removably attachable to electronic devices for use as the front polarizers for the liquid crystal display modules included with the electronic devices. The front polarizers are removably attachable so that they can be interchanged to alter display appearance for aesthetics, optical performance and/or other characteristics. For example, differently colored front polarizers can be exchanged to coordinate the appearance of the display with an exchangeable face plate of the electronic device.

Abstract: The present invention provides an electronic device that has an electronic display module that can be removed by a user and replaced with another display module. Display modules can be interchanged to alter the display appearance, to alter the display functionality, to upgrade to a higher end display or larger display, to switch to a different display technology, to replace non-functioning displays, and the like. In some embodiments, user input devices, such as key pads, can be removed along with the display module and replaced with a larger display module having a touch panel user interface.

Abstract: The present invention includes electronic devices having liquid crystal display modules and repositionable front polarizers. A viewer views the display module through a front polarizer, which can be repositioned to change the display appearance, enhance the display contrast, invert the image, increase ambient light exposure, provide privacy, or the like. Repositionable front polarizers can be tiltably and/or rotatably mounted in front of the display module, or can be remotely located, for example on a pair of polarizing eye glasses. The present invention also includes reflective liquid crystal displays that have internal front light guides disposed between a liquid crystal cell and a front polarizer. As such, the light from the front light guide can illuminate the liquid crystal cell without being attenuated by the front polarizer, resulting in a brighter front lit display.

Abstract: A method for changing the appearance of liquid crystal display modules by exchanging front polarizers is disclosed. Polarizers can be provided that are removably attachable to electronic devices for use as the front polarizers for the liquid crystal display modules included with the electronic devices. The front polarizers are removably attachable so that they can be interchanged to alter display appearance for aesthetics, optical performance and/or other characteristics. For example, differently colored front polarizers can be exchanged to coordinate the appearance of the display with an exchangeable face plate of the electronic device. This can allow users to customize the look of the display.

Abstract: A polarizer has low color shift and is particularly well suited to use in an LCD display. The polarizer has a double pass color shift of |&Dgr;x|≦0.005 and |&Dgr;y|≦0.005 for illumination by a C-illuminant, and a double pass contrast modulation of at least 90%. The display includes two or more layers stacked together, at least one of the layers being an absorbing polarizer having a double pass color shift of |&Dgr;x|≦0.005 and |&Dgr;y|≦0.005 for illumination by a C-illuminant. A polarizer with a selected color shift is also used with a rear projection screen having a dispersing layer stacked together with first absorbing polarizer. The polarizer has a single pass color shift with at least one of &Dgr;x and &Dgr;y being negative under illumination by a C-illuminant, and a polarization co-efficiency greater than 90%.

Abstract: A brightness enhancement article that includes: (a) a transparent, flexible substrate; (b) a first major surface having an array of prisms with blunted or rounded peaks characterized by a chord width, cross-sectional pitch width, and radius of curvature in which the chord width is equal to about 20-40% of the cross-sectional pitch width and the radius of curvature is equal to about 20-50% of the cross-sectional pitch width; and (c) a second major surface characterized by a plurality of light scattering protrusions. The article has a haze value between about 20-60% and a transmission value no greater than about 94% when measured under conditions in which the first surface has a substantially planar topography.

Abstract: The present invention includes a structured optical film with variable pitch peaks and/or grooves to reduce the visibility of moire interference patterns and optical displays incorporating one or more layers of the film. The pitch variations can be over groups of adjacent peaks and/or valleys or between adjacent pairs of peaks and/or valleys.