Provided is a method in which, when configuring an HUD that produces a holographic image at a distance using a holographic optical element (HOE), an HOE capable of correcting aberrations generated by a projection optical system is manufactured and used to improve the quality of an HUD image. A method for manufacturing an HOE for HUD according to an embodiment of the present invention comprises the steps of: measuring aberrations generated by an optical system that projects an image of a display device; recording the measured aberrations in a master HOE; reproducing an aberrated wavefront of the optical system by playing the master HOE on a display plane on which the image of the display device is expressed; and causing an interference of the reproduced aberrated wavefront and a spherical wavefront irradiated from the HUD image plane on which the image of the display device is created, and recording the interference in the HOE. Accordingly, when configuring the HUD producing an image at a distance using the HOE, the quality of the HUD image can be improved by measuring aberrations in the projection optical system, creating a master HOE that reproduces the measured aberrations, and manufacturing a HOE that corrects the aberrations, and correcting aberrations generated in the projection optical system.

The head-up display apparatus includes a displaying device installed inside an instrument panel, an opening portion formed in the instrument panel, and a combiner disposed above the opening portion. An image of the displaying device is projected to the combiner through the opening portion. The displaying device is a segment display. The segment display includes a plurality of light sources and a character/symbol plate having a plurality of image informing parts. The combiner is made of a non-translucent dark plate or a semi-translucent dark smoke plate.

A method of manufacturing an optical element including, a first step of, after affixing a hologram forming material to a glass substrate having a marking portion, performing interference exposure on the hologram forming material, thereby forming a hologram layer at the glass substrate, and a second step of affixing the hologram layer peeled off from the glass substrate to a plastic substrate having a first alignment mark, wherein in the second step, the first alignment mark on the plastic substrate, and a second alignment mark formed at a position corresponding to the marking portion in the hologram layer during the interference exposure are used to implement positioning of the plastic substrate and the hologram layer.

A waveguide image combiner is used to transmit a monochrome or full-color image in an augmented reality display. The combiner uses multiple stacked substrates and multiple pairs of incoupling and outcoupling VHOEs to expand a first FOV and an image expander to expand the second or perpendicular FOV. This suitably provides an expanded FOV that offers a diagonal FOV≥50°, a horizontal FOV≥40 and a vertical FOV≥25°. The combiner also delivers a large horizontal eye box up to 20 mm and a vertical eye box of 10 mm while maintaining high light efficiency of the real scene (e.g. >80%). The system is able to use a light engine based on broadband (10 nm≤Δλ≤40 nm) LEDs and maintain a large horizontal field of view and high transmission of the real imagery. The approach resolves issues with current embodiments including astigmatism, image overlap, color balance, and small light engine pupils leading to reduced eye boxes.

An optical element includes a hologram layer, a resin substrate to which the hologram layer is adhered, and a holder portion that supports the resin substrate and has a thermal expansion coefficient smaller than that of the resin substrate. One of the holder portion and the resin substrate includes a contact surface along an axis extending in a plate thickness direction of the resin substrate, and the other of the holder portion and the resin substrate includes a pressing surface that presses the contact surface.

A power bank and holographic projection accessory intended for use with a portable electronic device. The accessory includes a holographic projection unit and an external power bank case attachable to the holographic projection unit. The external power bank case is configured to provide power to the holographic projection unit and to provide a video signal generated by the portable electronic device to the holographic projection unit. The holographic projection unit generates volumetric projections based upon the video signal.

A method for producing a curved substrate panel with a hologram includes producing a curved substrate panel from plastic by forming, injection moulding or injection-compression molding between a first mold half, which defines a predetermined desired geometry of a substrate surface, and a second mold half removing the first mold half from the second mold half and applying a holographic master to a surface of the first mold half, or of a further mold half fixing the first mold half or further mold half on the second mold half such that an empty gap of a predetermined constant thickness remains between the holographic master and the substrate surface, and filling this gap with a hologram-receiving material; and exposing the hologram-receiving layer formed between the substrate surface and the holographic master with a coherent light for forming a hologram defined by the holographic master.

A diffractive optical member includes a hologram element, a support member that supports the hologram element by contacting the hologram element from one side, and a covering film member that is a first film member and covers the hologram element by contacting the hologram element from a side opposite to the one side. The covering film member includes a coupling portion that is in contact with the support member, and the coupling portion is separated from the hologram element.

A diffraction grating includes a substrate and a plurality of fringes supported by the substrate. The fringes run parallel to each other in a first direction. A refractive index of a material of the plurality of fringes is anisotropic, whereby a refractive index contrast of the diffraction grating depends on direction of electric field of an impinging light beam, and through that dependence is a function of an azimuthal angle of the impinging light beam. A dependence of the diffraction efficiency on the azimuthal angle is affected by the dependence of the refractive index contrast on the direction of electric field of an impinging light beam. A pupil-replicating waveguide may use such a diffraction grating as a coupler for in- our out-coupling image light.

An image display device includes, an imaging light generation part configured to generate an imaging light having a single color, a light-guiding plate, an incident side diffraction element provided at a light incident part of the light-guiding plate, and configured to cause the imaging light to enter the light-guiding plate, an exit side diffraction element provided at a light emitting part of the light-guiding plate, and configured to cause the imaging light propagating within the light-guiding plate to exit, and an angle dependent reflective film provided between the light-guiding plate and the exit side diffraction element, and having a reflectance varying depending on magnitude of a propagation angle of the imaging light, in which the reflectance for the imaging light propagating at a relatively small propagation angle is larger than the reflectance for the imaging light propagating at a relatively large propagation angle.