According to one embodiment, a display device including a display unit which emits display light, an optical element which includes a first surface on the display unit side, and a second surface on a side opposite to the first surface, and transmits and reflects incident light, and a retroreflective element provided on the first surface side or the second surface side, wherein the retroreflective element includes first and second retroreflectors which retroreflect light made incident through the optical element, and a transmissive portion located between the first retroreflector and the second retroreflector.

According to one embodiment, a display device including a display unit which emits display light, an optical element which includes a first surface on the display unit side, and a second surface on a side opposite to the first surface, and transmits and reflects incident light, and a retroreflective element provided on the first surface side or the second surface side, wherein the retroreflective element includes first and second retroreflectors which retroreflect light made incident through the optical element, and a transmissive portion located between the first retroreflector and the second retroreflector.

Conventional retro-reflective static traffic signage is primarily constructed of either heavy metal containing high refractive index glass beads embedded in a film or narrow viewing angle corner cubes. Disclosed herein are embodiments of static display signage having polymer-based circularly symmetric convex protrusions absent of heavy metals which reflect light in a semi-retro-reflective manner with wider viewing angles.

Conventional retro-reflective static traffic signage is primarily constructed of either heavy metal containing high refractive index glass beads embedded in a film or narrow viewing angle corner cubes. Disclosed herein are embodiments of static display signage having polymer-based circularly symmetric convex protrusions absent of heavy metals which reflect light in a semi-retro-reflective manner with wider viewing angles.

Many in the space weather community consider our understanding of the buoyancy of the thermosphere and its effects on the orbits of satellites in Low Earth Orbit (LEO) to be insufficient during short time frames. Disclosed herein is an approach for making on-demand thermosphere buoyancy measurements using a deployable low mass retroreflector with CubeSat-like dimensions. A CubeSat storing many retroreflectors can dispense one or more of these passive satellites according to a predetermined schedule or on-command, in response to an observed space weather phenomenon like a coronal mass ejection. With measurements of the orbit decay from these passive satellites, a better understanding of the relationship between space weather and orbital decay can be established with relatively low cost.

Many in the space weather community consider our understanding of the buoyancy of the thermosphere and its effects on the orbits of satellites in Low Earth Orbit (LEO) to be insufficient during short time frames. Disclosed herein is an approach for making on-demand thermosphere buoyancy measurements using a deployable low mass retroreflector with CubeSat-like dimensions. A CubeSat storing many retroreflectors can dispense one or more of these passive satellites according to a predetermined schedule or on-command, in response to an observed space weather phenomenon like a coronal mass ejection. With measurements of the orbit decay from these passive satellites, a better understanding of the relationship between space weather and orbital decay can be established with relatively low cost.

The disclosed retroreflective element includes a highly durable core with an ionic copolymer and a plurality of beads. These disclosed retroreflective properties remain intact even after continued application of external forces and stresses. Further, the ionic copolymer allows for beads to be loaded into the ionic copolymer of the core, securely disposed around the perimeter of the core, or both.

The disclosed retroreflective element includes a highly durable core with an ionic copolymer and a plurality of beads. These disclosed retroreflective properties remain intact even after continued application of external forces and stresses. Further, the ionic copolymer allows for beads to be loaded into the ionic copolymer of the core, securely disposed around the perimeter of the core, or both.

A system for imaging in the air including an image source, a transflector, and an retroreflective element. Light rays emitted by the image source are reflected by the transflector to irradiate on the retroreflective element, and are subjected to reflection on the retroreflective element, before being emitted along an original incident path in an opposite direction and being transmitted through the transflector to form a real image. By means of the present system, it is possible to directly present images in the air, even in vacuum, without the aid of any medium.

A lens system includes a first lens array assembly including a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses, and a second lens array assembly including a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses. The first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that light diverging from an object at a plane disposed at an object conjugate distance from the first lens array assembly reconverges at an image plane after passing through the first and second lens array assemblies. The image plane is disposed at an image conjugate distance from the second lens array assembly in accordance with the object conjugate distance.