Abstract: A light guide (100) comprises a light guide plate (110) with an illumination region (111). The light guide plate has a first main surface (112) and a second main surface (113) opposite to the first main surface, and comprises an out-coupling arrangement (120) for coupling light (150) propagating in the light guide plate out of the light guide plate through the first and/or the second main surface in the illumination region. The out-coupling arrangement comprises first out-coupling stripes (121) extending over the illumination region, each first out-coupling stripe defining a horizontal extension of a first light channel (141) in the light guide plate and being configured to couple light propagating substantially in a first direction along the first light channel, out of the light guide plate. Adjacent first out-coupling stripes are separated by an intermediate region (124) with light coupling properties substantially different from those of the first out-coupling stripes.

Abstract: A light guide structure (100) has a first main surface (101) and an opposite second main surface (102) and is configured to guide light in the light guide structure via total internal reflections at the first and the second main surfaces. The light guide structure comprises an out-coupling arrangement (120) configured to couple light propagating in the light guide structure out of it through the first and/or the second main surface. The light guide structure comprises two cladding layers (1111, 1112) and a core layer (110) sandwiched between the cladding layers, the core layer comprising a core material and the cladding layers comprising cladding materials, respectively. The core material has its elasticity higher than the elasticities of the cladding materials, and its refractive index for a design wavelength substantially the same as the refractive indices of the cladding materials.

Abstract: A light guide (100) comprises a light guide plate (110) with an illumination region (111). The light guide plate has a first main surface (112) and a second main surface (113) opposite to the first main surface, and comprises an out-coupling arrangement (120) for coupling light (150) propagating in the light guide plate out of the light guide plate through the first and/or the second main surface in the illumination region. The out-coupling arrangement comprises first out-coupling stripes (121) extending over the illumination region, each first out-coupling stripe defining a horizontal extension of a first light channel (141) in the light guide plate and being configured to couple light propagating substantially in a first direction along the first light channel, out of the light guide plate. Adjacent first out-coupling stripes are separated by an intermediate region (124) with light coupling properties substantially different from those of the first out-coupling stripes.

Abstract: A light guide structure (100) has a first main surface (101) and an opposite second main surface (102) and is configured to guide light in the light guide structure via total internal reflections at the first and the second main surfaces. The light guide structure comprises an out-coupling arrangement (120) configured to couple light propagating in the light guide structure out of it through the first and/or the second main surface. The light guide structure comprises two cladding layers (1111, 1112) and a core layer (110) sandwiched between the cladding layers, the core layer comprising a core material and the cladding layers comprising cladding materials, respectively. The core material has its elasticity higher than the elasticities of the cladding materials, and its refractive index for a design wavelength substantially the same as the refractive indices of the cladding materials.

Abstract: A light guide having a light guide body plate having a plurality of elongated light channels extending substantially parallel to each other; the light guide having an out-coupling arrangement for coupling light propagating in the light channels out of the light guide body plate through the first and/or the second main surface. In a horizontal transverse direction, each light channel is confined between two confining stripes formed of a solid confining material having a second refractive index lower than the first refractive index, confining stripes between two adjacent light channels having a height less than the thickness of the light guide body plate.

Abstract: A light guide having a light guide body plate having a plurality of elongated light channels extending substantially parallel to each other; the light guide having an out-coupling arrangement for coupling light propagating in the light channels out of the light guide body plate through the first and/or the second main surface. In a horizontal transverse direction, each light channel is confined between two confining stripes formed of a solid confining material having a second refractive index lower than the first refractive index, confining stripes between two adjacent light channels having a height less than the thickness of the light guide body plate.

Abstract: An arrangement (20) for coupling light into a plate-like light guide (25) having two surfaces (23, 24) on opposite sides of the light guide comprises an in-coupling diffraction grating (21) for diffracting an external light beam (26) incident on said in-coupling diffraction grating into the light guide in a direction enabling the in-coupled light beam to propagate within the light guide via total internal reflections at the light guide surfaces (23, 24). According to the present invention, the arrangement further comprises a deflection member (22) arranged to deflect the beam (27) initially diffracted by the in-coupling diffraction grating (21), before it hits the in-coupling diffraction grating again, out of the path determined by the in-coupling diffraction grating in order to reduce out-coupling of the already in-coupled light through the in-coupling diffraction grating.

Abstract: An arrangement (20) for coupling light into a plate-like light guide (25) having two surfaces (23, 24) on opposite sides of the light guide comprises an in-coupling diffraction grating (21) for diffracting an external light beam (26) incident on said in-coupling diffraction grating into the light guide in a direction enabling the in-coupled light beam to propagate within the light guide via total internal reflections at the light guide surfaces (23, 24). According to the present invention, the arrangement further comprises a deflection member (22) arranged to deflect the beam (27) initially diffracted by the in-coupling diffraction grating (21), before it hits the in-coupling diffraction grating again, out of the path determined by the in-coupling diffraction grating in order to reduce out-coupling of the already in-coupled light through the in-coupling diffraction grating.

Abstract: An arrangement (20) for coupling light into a plate-like guide (25) having two surfaces (23, 24) on opposite sides of the light guide comprises an in-coupling diffraction grating (21) for diffracting an external light beam (26) incident on said in-coupling diffraction grating into the light guide in a direction enabling the in-coupled light beam to propagate within the light guide via total internal reflections at the light guide surfaces (23, 24). According to the present invention, the arrangement further comprises a deflection member (22) arranged to deflect the beam (27) initially diffracted by the in-coupling diffraction grating (21), before it hits the in-coupling diffraction grating again, out of the path determined by the in-coupling diffraction grating in order to reduce out-coupling of the already in-coupled light through the in-coupling diffraction grating.

Abstract: A transmission type optical element (10) comprises a surface relief micro-grating (5, 9) for guiding light (13) propagating through the optical element. According to the present invention, at least a portion (5) of the thickness of the optical element (10) is formed of a colored material (4) so as to make the optical element colored.

Abstract: A transmission type optical element (10) comprises a surface relief micro-grating (5, 9) for guiding light (13) propagating through the optical element. According to the present invention, at least a portion (5) of the thickness of the optical element (10) is formed of a colored material (4) so as to make the optical element colored.

Abstract: An optical diffraction grating (10) is produced by providing a mold (50) having a plurality of inclined grooves (58), which have a small clearance angle (?). The mold (50) is covered by a curable material (M1). Said material is subsequently cured, i.e. hardened, and separated from the mold (50) to provide the diffraction grating (10). The inclined orientation of the grooves (58) allows expansion or contraction of the grating during the curing and separation steps such that the probability of mold breakage may be reduced. The inclined orientation of the grooves may also facilitate the separation of the grating (10) from the mold (50).