Abstract:
There is herein defined optics (e.g. an array of optics) forming an optical beam to either produce a collimated or diverging/converging beam emerging from a virtual source point to illuminate a hologram. There is also described an optical beam illuminating a reflection hologram from the front and a further configuration where an optical beam combined with a holographic optical element (HOE) mirror enables rear illumination of a reflection hologram.
Abstract:
A method of manufacturing a master for producing a hologram device is provided. A first master is produced with a compensating angle. The second master is produced from the first master with an index matching material to reduce the interference pattern caused by internal reflections within the holographic plate of the master. The hologram device has a relatively narrow angle of reconstruction to provide visibility from a nearly perpendicular light source such as the headlight of an on-coming vehicle.
Abstract:
A substrate includes a diffracting structure providing a hologram (20, 6). The diffracting structure encodes a holographic image so that thatholographic image is produced in response to reference light being incident on a major surface of the substrate at an angle of incidence with respect to the said major surface of the substrate, wherein the angle of incidence is no more than 20°.
Abstract:
A substrate-guided holographic diffuser has a light-guide section configured to in-couple light and transmit the light within itself via total internal reflection. It can also have a brightness enhancement section that recycles non-diffracted light within the light-guide section. A hologram section that receives light from the light-guide section has a holographic structure defining acceptance conditions and is positioned relative to the internally reflected light such that the internally reflected light meets the acceptance conditions of the holographic structure. The internally reflected light is out-coupled by the holographic structure as a projected image of light scattered from a diffuser.
Abstract:
The invention concerns a method for controlling depth or depth-of-focus in 3D image reconstructions, in particular for: A) Controlling the depth with the aim to synthesize a holography dynamic 3D scene; such a scene can be either numerically reconstructed or holographically projected for 3D display purposes by means of optical reconstruction through Spatial Light Modulator (SLM); B) controlling the focus to extend the depth of focus and have two object at different distance simultaneously in focus by digital holography; The method according to the invention can be applied with few differences both to the usual holograms and to the Fourier ones. The invention further concerns a holographic apparatus implementing the method according to the invention.
Abstract:
There is herein described apparatus and methods for displaying holograms. At least one aspect of the invention is to provide a compact and self-contained lighting system for a display hologram, which can produce high quality images and which is substantially insensitive to stray light.
Abstract:
A method of digital holography comprises illuminating an object S, rotating the object wavefield relative to a digital holographic sensor CCD so that the object wavefield is shifted across the recording surface of the sensor, and recording a plurality of digital holograms ("input holograms") at respective angular positions of the object wavefield. The input holograms are combined to create an output digital hologram having a higher resolution that any of the input holograms. The object wavefield may be rotated by rotating the object (in the case of a 2-D object) or by rotating a mirror interposed between the object and the sensor (in the case of a 3-D object).
Abstract:
Masterhologramm und Verfahren sowie Vorrichtung zum Herstellen eines Masterhologramms für ein Kontaktkopierverfahren Die Erfindung betrifft ein Verfahren zum Herstellen eines Masterhologramms (45) für ein Kontaktkopierverfahren, ein solches Masterhologramm (45) sowie ein Verfahren zum Herstellen von individualisierten Hologrammen (345) und individualisierte Hologramme (345), die mit einem solchen Masterhologramm (45) im Kontaktkopierverfahren hergestellt sind. Das Verfahren zum Herstellen eines Masterhologramms (45) umfasst die Schritte: Anordnen eines diffusen Streuers (10), einer Blende (20), einer Fourier-Linse (30) und eines holografischen Aufzeichnungsmaterials (40) auf einer optischen Anordnungsachse (3), so dass eine optischen Achse (31) der Fourier-Linse (30), eine Oberflächennormale (41) des holografischen Aufzeichnungsmaterials (40) und eine Oberflächennormale (26) einer Blendenöffnungsebene (25) der Blende (20) kollinear zur optischen Anordnungsachse (3) sind, wobei die Blende (20) zwischen dem diffusen Streuer (10) und der Fourier-Linse (30) unmittelbar an den diffusen Streuer (10) angrenzend angeordnet wird und der diffuse Streuer (10) in einer Brennebene (32) der Fourier-Linse (30) angeordnet wird und und kohärentes erstes Licht (110) auf den diffusen Streuer (10) eingestrahlt wird, um hierdurch das diffus gestreutes Licht (115) zu erzeugen, welches mittels der Blende (10) eingegrenzt und mittels der die Fourier-Linse (30) in das holografische Aufzeichnungsmaterial (40) als Objekt-Licht (119) geleitet wird und zum dem ersten kohärenten Licht (110) kohärentes zweites kohärentes Licht (120) von einer der Fourier- Linse (30) abgewandten Seite in das holografische Aufzeichnungsmaterial (40) als Referenzlicht (129) eingestrahlt wird, um in dem holografischen Aufzeichnungsmaterial (40) ein Reflexionsvolumenhologramm (45) auszubilden.
Abstract:
Imaging apparatus and methods using diffraction-based illumination are disclosed. An example apparatus includes a diffraction grating to redirect light from a light source toward a sample to thereby illuminate the sample. The example apparatus also includes an image sensor to detect a diffraction pattern created by the illuminated sample.