The invention relates to an optical imaging system (100) and a device for floating display, and a surround-view display device (2000). The optical imaging system (100) sequentially defines, along the optical axis thereof, an object plane (10), a first image plane (101) and a second image plane (102), and the optical imaging system (100) comprises at least one imaging unit (110) arranged between the object plane (10) and the first image plane (101) on the optical axis, with the at least one imaging unit (110) having different light converging capabilities in a first direction and in a second direction, and the first direction and the second direction being orthogonal to the optical axis, respectively; and a main diffusion screen (120) diverging light in the second direction, the optical imaging system (100) being configured such that a light beam from a point on the object plane (10) forms a line image in the first direction on the first image plane (101), and the light beam from a point on the object plane (10) forms a line image in the second direction on the second image plane (102), with the second image plane (102) being a floating image plane.

A photonic reflector device includes a first layer, a second layer, and a third layer. The first layer, which functions as a retro-reflector, is formed of a first material contacting a second material and having a non-planar interface therebetween. The second layer, which functions as a photonic crystal, includes third and fourth materials that have different refractive indices from one another and are configured such that the second layer has a periodic optical potential along at least one dimension. The third layer, which functions as a Lambertian scatterer, includes a plurality of inclusions in a first matrix material. In combination, the layers may be optimized to synergistically reflect targeted wavelengths and/or polarizations of light.

A photonic reflector device includes a first layer, a second layer, and a third layer. The first layer, which functions as a retro-reflector, is formed of a first material contacting a second material and having a non-planar interface therebetween. The second layer, which functions as a photonic crystal, includes third and fourth materials that have different refractive indices from one another and are configured such that the second layer has a periodic optical potential along at least one dimension. The third layer, which functions as a Lambertian scatterer, includes a plurality of inclusions in a first matrix material. In combination, the layers may be optimized to synergistically reflect targeted wavelengths and/or polarizations of light.

Retroreflecting articles are described. In particular, retroreflecting articles including retroreflecting layers and contrast reduction layers are described. The contrast reduction layer decreases the near infrared retroreflective efficiency of the retroreflecting substrate by more than 50%.

Retroreflecting articles are described. In particular, retroreflecting articles including retroreflecting layers and contrast reduction layers are described. The contrast reduction layer decreases the near infrared retroreflective efficiency of the retroreflecting substrate by more than 50%.

Described herein is a photovoltaic module, which includes PV cells capable of converting light incoming from a front side and from a rear side (3) and a transparent rear side including a rear surface carrying a structured layer (9), where the lower surface of the structured layer (9) is the lower surface of the module, and where the surface of layer (9) is structured by parallel V-shaped grooves of depth h2 or less than h2, where the lateral faces of the grooves of depth less than h2 form a groove angle beta and adjacent faces of neighbouring grooves form a peak of apex angle alpha, characterized in that h2 is from the range 5 to 200 micrometer, and each pair of neighbouring grooves includes one groove of depth h2 and one groove of depth (h2−h1), where h1 ranges from 0.1 h2 to 0.9 h2.

An optical scanning device includes a control unit, a light deflector, light detection units, and a light source. A mirror unit of the light deflector has a flat reflection part for generating scanning light and a groove-shaped reflection part for generating twice reflected light, and performs reciprocating rotation about a rotation axis. The light detection units are disposed at positions on the scanning trajectory of the scanning light where the twice reflected light is received, and are each divided into light detectors in the scanning direction of the scanning light by a division line. The control unit detects the deflection angle θ of the mirror unit based on both the output of the light detector and the output of the light detector.

This invention is a novel retroreflective traffic stripe comprising a widely spaced repeating pattern of linear light turning prisms over cube corner retroreflective prisms in a critical optimal configuration. The light turning prisms comprise at least two exposed surfaces, one approximately vertical facing the headlights of oncoming traffic, and another opposing the first and sloped by approximately 45 degrees. The approximately vertical surface efficiently accepts light from the headlights and transmits such light to the sloped surface which totally internally reflects such light downward onto an array of cube corner retroreflective prisms, which totally internally reflect such light in approximately the reverse direction. Such reflected light once more encounters the sloped face of the light turning prisms which totally internally reflects the light toward the approximately vertical surface, where such light exits and returns toward the headlights and, more importantly, toward the eyes of the driver of the vehicle.

An outer wall material includes a first transparent member integrally or separately including a transparent plate material and a prism portion; and a reflection member provided on a second side of the prism portion of the first transparent member. The prism portion causes the reflection member to collect light whose angle with respect to a normal line of the plate material is equal to or greater than a predetermined angle and to retro-reflect the collected light, and transmits light whose angle with respect to the normal line of the plate material is less than the predetermined angle.

A vehicle surface 30, preferably wherein the vehicle is an aircraft, is described. The vehicle surface 30 comprises thereon and/or therein a set of retroreflectors 300, including a first retroreflector 300A, configured to reflect, at least in part, incident hostile light towards a source thereof.