The light-guiding optical unit (1) for a light device of motor vehicles comprises a light guide (2) that comprises at least one routing surface (3), and at least one light source (4) to generate light rays (10). The light-guide (2) further comprises a top surface (12) at least a part of which is constituted by the output surface (15), and a bottom surface (13) opposite the top surface (12) and fitted with a prismatic structure (16) comprising reflective surfaces (7). The routing surface (3) and the reflective surfaces (7) are mutually arranged in such a way that the routing surface (3), by means of routing by refraction on this surface (3) or reflection from this surface (3), directs light rays (10) to the prismatic structure (16) in such a way that it directly lights up only the reflective surfaces (7) with the light rays (10), the reflective surfaces (7) being configured to direct light rays (10) that have fallen onto them this way directly from the routing surface (3) to the output surface (15) in such a way that the light rays (10) can exit from the light guide (2) through the output surface (15).

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.

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 privacy display comprises a liquid crystal spatial light modulator, a switchable retarder and a passive compensation retarder arranged between a pair of polarisers. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without change of image contrast, whereas off-axis light has reduced contrast to reduce the visibility of the display to off-axis snoopers over a wide polar angular range. In a wide angle mode of operation, the retardance of the switchable retarder is adjusted so that off-axis contrast is substantially unmodified.

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.

A privacy display comprises a spatial light modulator and a compensated switchable liquid crystal retarder arranged between first and second polarisers arranged in series with the spatial light modulator. In a privacy mode of operation, on-axis light from the spatial light modulator is directed without loss, whereas off-axis light has reduced luminance. The visibility of the display to off-axis snoopers is reduced by means of luminance reduction over a wide polar field. In a wide angle mode of operation, the switchable liquid crystal retardance is adjusted so that off-axis luminance is substantially unmodified.

A HUD system and light source apparatus can be manufactured with miniaturization at low cost. A head-up display apparatus includes: an image display apparatus generating image light to be projected; an optical system performing predetermined correction to the image light emitted from the image display apparatus; and a concave mirror reflecting the image light corrected by the optical system to project it onto a windshield or combiner. The image display apparatus includes: a solid light source; a collimating optical system converting, into parallel light, the light from the solid light source; a lighting optical system configured by an optical member that polarizes a direction of a light beam generated by the collimating optical system and simultaneously expands a width of the light beam; and a display apparatus, the image display apparatus being configured to be arranged across and opposite the optical system on an optical axis of the concave mirror.

A planar illumination device according to an embodiment includes a light source and a light guide plate. The light source emits light in a predetermined direction. The light guide plate includes a side surface, an emission surface as one of principal surfaces, and a back surface as the other principal surface, the back surface including a prism formed thereon, the prism emitting, through an emission surface, light emitted from the light source and entered from the side surface. The prism includes, at a section parallel to the predetermined direction, a first region substantially parallel to the emission surface and a second region tilted relative to the emission surface, the first region and the second region extending in a direction oblique to the predetermined direction.

Provided is a light source apparatus that is small and lightweight, has high light utilization efficiency, and is easily utilizable as a modularized, planar light source. The light source apparatus 10 has a light source unit including a plurality of LED elements 14, a LED collimator 15 including a plurality of collimator elements each arranged on a light-emitting axis of each of the plural LED elements 14, and a light guide 17 disposed on an emission side of the LED collimator 15. The light guide 17 includes an incidence portion 171 having an incidence surface on which light on the light-emitting axis from the LED elements 14 is incident, and an emission portion 173c having an emission surface emitting light, and has a free-form surface shape for realizing predetermined light distribution control on at least one of the incidence surface and the emission surface.

A display device includes a light source, a light-directing element, a reflective display element, and a microlens array. The light-directing element is disposed on the transmission path of a lighting beam provided by the light source for projecting the lighting beam toward the first direction. The reflective display element includes a plurality of micro-image units, wherein each micro-image unit converts the lighting beam projected from the light-directing element into an sub-image beam and reflects the sub-image beam. The microlens array is disposed on the transmission path of the sub-image beams, wherein the light-directing element is located between the microlens array and the reflective display element. The microlens array includes a plurality of microlenses. Each sub-image beam pass throughs the light-directing element and is projected to an aperture by the corresponding microlens, and the sub-image beams pass through the aperture to form an image beam.