A liquid crystal display device includes a narrow light distribution backlight, a transparent backlight disposed in front of the narrow light distribution backlight, and a transmissive liquid crystal panel in a horizontal electrical field mode. The transparent backlight is a sidelight type backlight including a transparent light guide plate disposed to face the narrow light distribution backlight and a light source disposed on a side surface of the light guide plate. Prism-like irregularities extending in a vertical direction are formed on a surface of the light guide plate on a side of the narrow light distribution backlight. An electrode having a comb-like shape extending in a horizontal direction is disposed in each pixel of the transmissive liquid crystal panel.

A luminaire configured to emit light in different directions. The luminaire may include a frame and optical waveguides disposed in the frame and positioned at different angles relative to one another to direct light outward in multiple different directions. At least one LED may be associated with each optical waveguide. A shield may be associated with the frame and configured to reduce the light from being directed in one or more of the different directions.

An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Retarder stack arrangements are provided to reduce the display visibility to snoopers located in polar viewing regions of the display while achieving minimal reduction of head-on luminance. Further visibility of light reflections from automotive windscreens may be reduced.

A cavity illumination system according to the present disclosure may include one or more illumination elements composed of a transparent or semi-transparent, biocompatible sterilizable polymer and one or more illumination sources. The sterilizable polymer operates as a waveguide. An illumination element may incorporate micro structured optical components such as for example gratings, prisms and or diffusers to operate as precision optics for customized delivery of the light energy. The micro structured optical components may also be used to polarize and/or filter the light energy entering or exiting the illumination element.

An imaging directional backlight apparatus includes a waveguide and light source array for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure in which steps may include extraction features optically hidden to guided light, propagating in a forward direction. Returning light propagating in a backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. Viewing windows are formed through imaging individual light sources and defines the relative positions of system elements and ray paths. Alignment of the waveguide to mechanical and optical components may be provided by surface relief features of the waveguide arranged in regions adjacent the input surface and intermediate the light emitting regions of the light sources. Efficient, uniform operation may be achieved with low cross talk for application to autostereoscopic and privacy modes of operation.

A transparent light-guiding unit for guiding imaging light, a positioning portion provided at the transparent light-guiding unit, a camera for performing space detection of an external space, and a camera holder that contacts the positioning portion and is attached to the transparent light-guiding unit, and holds the camera are provided. In this case, the camera holder contacts the positioning portion, thus, when the camera is attached to the transparent light-guiding unit, high positional accuracy is reliably maintained.

A backlight includes a directional waveguide and a light source array, for providing large area directed illumination from localized light sources. Interfaces are provided between the directional waveguide and optical components adjacent the directional waveguide such that the coefficient of friction at the waveguide interfaces is greater than the coefficient of friction at least one outer interface on each side of the waveguide in the stack. Damage from compressive forces on the optical stack may be reduced, achieving improved optical performance and lifetime. Privacy display, low stray light display and autostereoscopic display may be provided with high uniformity, long lifetime and reduced cost mechanical components.

A luminaire that includes a light emitting diode (LED) array configured to produce light in a first direction along a propagation path. An optical waveguide is spaced apart from the LED array by a gap and with the optical waveguide and the gap disposed along the propagation path. The optical waveguide is configured to receive the light along the propagation path at the first waveguide surface and transmit the light away from the luminaire at the second waveguide surface. A housing is mounted to the LED array and the optical waveguide and includes a slot directly adjacent to the gap.

An imaging directional backlight apparatus including a waveguide, a light source array, for providing large area directed illumination from localized light sources. The waveguide may include a stepped structure, in which the steps may further include extraction features optically hidden to guided light, propagating in a first forward direction. Returning light propagating in a second backward direction may be refracted, diffracted, or reflected by the features to provide discrete illumination beams exiting from the top surface of the waveguide. In operation, luminance streaks and bright illumination regions may be formed due to undesirable imaging characteristics from the structure of the Fresnel mirror. Fresnel mirror draft facets and reflective facet microstructures are provided that achieve reduction of visibility of light streaks and bright illumination regions.

Disclosed is an imaging directional backlight including an array of light sources, and a control system arranged to provide variable distribution of luminous fluxes, scaled inversely by the width associated with the respective light sources in the lateral direction, across the array of light sources. The luminous intensity distribution of output optical windows may be controlled to provide desirable luminance distributions in the window plane of an autostereoscopic display, a directional display operating in wide angle 2D mode, privacy mode and low power consumption mode. Image quality may be improved and power consumption reduced.