System and methods for efficiently generating a high quality patterned-phase-only hologram that can be displayed on a single device. A digital image of a holographed subject is measured as a distribution of the intensity of pixels in the image, or as an intensity image, and uniformly partitioned into a plurality of non-overlapping image blocks. A phase mask is applied to each pixel in each image block and assigned a value in the range of [0,2). The pixels are modulated with a phase value corresponding to the value applied by the phase mask, creating a modified intensity image. A complex hologram is generated from the modified intensity image. The complex hologram is generated utilizing a fast hologram generation process and then converted into a patterned-phase-only hologram. A short sequence of the patterned-phase holograms can be displayed to enhance the visual quality of the displayed holographic images.

There is provided a holographic display device, which includes a display panel including plural sub-pixels, wherein each sub-pixel includes plural subdivided pixels, and each subdivided pixel has an adjustable light transmittance; a backlight, configured to provide reference light to the display panel; a phase adjustment layer, including plural transparent phase adjustment components, wherein each phase adjustment component is configured to adjust a phase of a light ray transmitted through the phase adjustment component, and the phase adjustment components corresponding to a single sub-pixel have phase adjustment amounts different from each other; and a controller, configured to obtain a target phase of a light ray to be transmitted through each sub-pixel, and determine a target subdivided pixel, which corresponds to the target phase, in each sub-pixel, and further configured to obtain a target intensity of the light ray, and adjust a light transmittance of the target subdivided pixel.

A head-up display for a windscreen having spatially variant optical power. The head-up display includes a diffuser arranged to display an image. The diffuser is shaped to compensate for the spatially variant optical power of the windscreen. A holographic projector may be provided, which is arranged to project the image for display onto the diffuser and includes a spatial light modulator arranged to apply a phase-delay distribution to incident light. The phase-delay distribution includes phase-only data representative of an object. The projector further includes Fourier transform means arranged to perform a Fourier transform of phase modulated light received from the spatial light modulator and to form the image on the diffuser.

A method for generating a holographic image, a signal processor, a holographic image display device, a wearable apparatus, and an onboard head-up display apparatus. The method comprises: performing holographic transformation on the basis of a target amplitude phase distribution of a target image to obtain a holographic phase image; performing phase quantization of the holographic phase image to obtain a quantized holographic image; performing inverse holographic transformation of the quantized holographic image to obtain a reconstructed image; if the reconstructed image satisfies a preset condition, determining that the quantized holographic image is a target holographic image; if not, constraining the amplitude phase of the reconstructed image and, on the basis of the amplitude phase constrained image, continuing iteration. The present method can rapidly and effectively implement monochrome or multi-colour high contrast ratio, low noise real-time holographic image generation and display, and the imaging distance can be freely adjusted.

An optical device is provided that exhibits a variable optical effect upon illumination. The optical device has a diffractive structure comprising: a portion of a first kinoform diffractive structure that encodes a first image, arranged to form a first diffractive region (11) of the diffractive structure; and a portion of a second kinoform diffractive structure that encodes a second image, arranged to form a second diffractive region (13) of the diffractive structure; wherein the first diffractive region and the second diffractive region are laterally separate; and each of the first diffractive region and the second diffractive region are discernible by the naked human eye. Methods of manufacture of such optical devices are also disclosed.

An apparatus and method to produce a hologram of an object includes an electromagnetic radiation assembly configured to receive a received electromagnetic radiation, such as light, from the object. The electromagnetic radiation assembly is further configured to diffract the received electromagnetic radiation and transmit a diffracted electromagnetic radiation. An image capture assembly is configured to capture an image of the diffracted electromagnetic radiation and produce the hologram of the object from the captured image.

A phase modulation structure includes a recording surface including phase angle recording regions in a plurality of calculated element regions corresponding to reconstruction points of an image on a one-to-one basis, each phase angle recording region being formed of a plurality of unit blocks in each of which a phase angle is recorded, the phase angle being calculated based on a phase that is a sum of a plurality of phases of light from the corresponding reconstruction points; and a representative area that is one of divisions of the calculated element region, the representative area being obtained by radially dividing the calculated element region centered on a point on the calculated element region, the point being obtained by extending a normal line from the corresponding reconstruction point to the calculated element region on the recording surface.

An optical film including a recording surface on which a plurality of unit blocks is disposed at regular intervals. For these unit blocks, phase components of light from a reconstruction point are calculated. The recording surface includes a calculated element region provided with an array of the unit blocks for which phase components of light from the reconstruction point are calculated for reproduction of an image. A first image is a monotone reconstruction image having even brightness, and a second image is a grayscale image having brightness gradation.

The present invention relates to a system and method for high quality speckle-free phase-only computer-generated holographic image projection. The present invention more particularly relates to a holographic image display system comprising a spatial light modulator to phase modulate light from at least one light source configured to illuminate said spatial light modulator and to provide a phase hologram and projection optics to project said phase modulated light to generate an image formed by said displayed hologram onto an image plane.

There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).