An illumination device has a coherent light source, an optical device that diffuses the plurality of coherent light beams and illuminates a predetermined illumination area, and a timing control unit that individually controls incident timing of the plurality of coherent light beams to the optical device or illumination timing of the illumination area, wherein the optical device has a plurality of diffusion regions, the diffusion regions being provided corresponding to the plurality of coherent light beams, the plurality of diffusion regions illuminate the illumination range by diffusion of incident coherent light beams, the plurality of diffusion regions have a plurality of element diffusion regions, the plurality of element diffusion regions illuminate partial regions in the illumination area by diffusion of incident coherent light beams, and at least parts of the partial regions illuminated by the plurality of element diffusion regions are different from one another.

An illumination apparatus for reducing speckle effect in light reflected off an illumination target includes a laser; diffuser positioned in an optical path between an illumination target and the laser to diffuse collimated laser light in a planar fan of diffused light that spreads in one dimension across at least a portion of the illumination target; and a beam deflector to direct the collimated laser light incident on the beam deflector to sweep across different locations on the linear diffuser within an exposure time for illumination of the illumination target by the diffused light. The different locations span a distance across the linear diffuser that provides sufficient uncorrelated speckle patterns, at an image sensor, in light reflected from an intersection of the planar fan of light with the illumination target to add incoherently when imaged by the image sensor within the exposure time.

The present technology aims to provide a diffraction element that functions like a transmissive hologram, and more particularly, aims to provide a diffraction element suitable for forming an image projection system. The present technology provides a composite diffraction element that includes a stack structure including a first diffraction element, a second diffraction element, and a third diffraction element in this order. The second diffraction element diffractively reflects light that has passed through the first diffraction element and reached the second diffraction element, toward the first diffraction element. The first diffraction element diffractively reflects the light diffractively reflected by the second diffraction element, toward the third diffraction element. The third diffraction element transmits the light diffractively reflected by the first diffraction element, and diffractively reflects zeroth-order light that has passed through the first diffraction element and the second diffraction element.

A method of manufacturing a part with an anti-counterfeit feature is provided. The method includes providing a part to be marked for anti-counterfeiting. The part is provided with a radiation impacting feature on or within the part. The radiation impacting feature is configured to at least one of (i) prevent accurate imaging of at least a portion of the part and (ii) provide unique authentication of the part.

A lighting device is provided, comprising a spatially extended light source with a light-emitting surface greater than 0.5 mm.sup.2 and also an aspherical TIR lens, which is configured to collimate light from the spatially extended light source, and a refractive diffuser configured to generate a lighting distribution on the basis of the collimated light.

A reflective material comprising a multilayered array of particles encapsulated by a matrix material, the reflective material defining a primary surface, the reflective material exhibiting: (i) visible retroreflection of incident radiation, wherein a wavelength of visible retroreflected radiation decreases from a first visible wavelength at a first angle to the primary surface to a second, shorter wavelength of visible retroreflected radiation as the viewing angle to the primary surface increases; and (ii) Bragg diffraction of the incident radiation, wherein the wavelength of radiation Bragg diffracted normal to the primary surface is longer than the wavelength of visible radiation, such that no visible radiation is retroreflected or Bragg diffracted in a direction normal to the primary surface.

An optical system providing a “living camo”, a color and form changing camouflage achieved from a substantially planar transparent base film substrate having a first side and a second side, with the first side having an optical surface composed of an array of optical micro-lenses, and with the second side having a colorized camouflage pattern, such that the lens array on the first side interacts with the colorized camouflage pattern on the second side to exhibit a color and or form change when viewed from the first side at differing angles, and a method of manufacture same.

An optoelectronic light emitting device includes a light emitting diode configured to emit a first radiation, a conversion layer including at least one planar quantum well configured to convert the first radiation into a second radiation, by photoluminescence, a grating for extracting the second radiation being etched on an upper face of the layer, and a lateral reflector having a reflective surface which extends facing part at least of a lateral surface of the conversion layer.

A light diffraction film includes a transparent substrate; and a light diffraction layer containing a binder resin and particles, in which an average primary particle diameter of the particles is 1 μm to 10 μm, and a coverage of a surface of the transparent substrate covered with the particles is 70% to 90%.

An image display apparatus according to one embodiment of the present disclosure includes: an output section that outputs projection light along a predetermined axis; an irradiated member to be irradiated with the projection light; and a first optical member that is disposed downstream of the irradiated member on a light path of the projection light, and reflects or diffuses a portion of the projection light that has transmitted through the irradiated member.