A display system comprising a first plurality of pixels, a second plurality of pixels, a first Fourier transform lens and a second Fourier transform lens. The first plurality of pixels is arranged ranged to display first holographic data corresponding to a first holographic reconstruction and receive light of a first wavelength. The a second plurality of pixels is arranged to display second holographic data corresponding to a second holographic reconstruction and receive light of a second wavelength. The first Fourier transform lens is arranged to receive spatially modulated light having a first wavelength from the first plurality of pixels and perform an optical Fourier transform of the received light to form the first holographic reconstruction at a replay plane, wherein the first holographic reconstruction is formed of light at the first wavelength. The second Fourier transform lens is arranged to receive spatially modulated light having a second wavelength from the second plurality of pixels and perform an optical Fourier transform of the received light to form the second holographic reconstruction at the replay plane, wherein the second holographic reconstruction is formed of light at the second wavelength. The optical path length from the first Fourier transform lens to the replay plane is not equal to the optical path length from the second Fourier transform lens to the replay plane.

A holographic projector comprises an image processing engine arranged to, a hologram engine and a display engine. The image processing engine is arranged to receive a source image for projection. The source image comprises a first colour component and a second colour component. The image processing engine is further arranged to form a first colour secondary image from the first colour component by nulling alternate pixel values of the first colour component in accordance with a first checkerboard pattern. The image processing engine is further arranged to form a second colour secondary image from the second colour component by nulling alternate pixel values of the second colour component in accordance with a second checkerboard pattern. The first checkerboard pattern is opposite to the second checkerboard pattern. The hologram engine is arranged to determine a first colour hologram corresponding to the first colour secondary image and a second colour hologram corresponding to the second colour secondary image. The display engine is arranged to form a first colour holographic reconstruction from the first colour hologram and a second colour holographic reconstruction from the second colour hologram.

A holographic projector having an optical path is described. The holographic projector comprises a first spatial light modulator arranged to display a first hologram, and a first light source. The first light source is arranged to illuminate the first spatial light modulator with light of a first wavelength such that a first holographic reconstruction corresponding to the first hologram is formed on a replay plane. The holographic projector further comprises a continuous block of transparent material. At least part of the optical path is formed through the continuous block of transparent material. The transparent material has a refractive index greater than air.

Embodiments of the present disclosure include apparatuses and method for a stacked light emitting diode (LED) hologram display. A stacked LED hologram display can include a first array of LEDs that are configured to emit red light received by a meta-optics panel configured to display a first portion of a holographic image, a second array of LEDs that are configured to emit green light received by a meta-optics panel configured to display a second portion of a holographic image, and a third array of LEDs that are configured to emit blue light received by a meta-optics panel configured to display a third portion of a holographic image. The stacked LED hologram display can include a number of actuators configured to adjust a position of a first array of LEDs in first direction and a second direction, adjust a position of a second array of LEDs in the first direction and the second direction, and adjust a position of a third array of LEDs in the first direction and the second direction.

A holographic display system including a first spatial light modulator panel and a second spatial light modulator panel is provided. The first spatial light modulator panel is configured to receive a first light with a first color, and generate a first diffracted light with the first color. The second spatial light modulator panel is configured to receive a second light with a second color and a third light with a third color, and respectively generate a second diffracted light with the second color and a third diffracted light with the third color. The first color, the second color, and the third color are different colors, and the first diffracted light, the second diffracted light and the third diffracted light form holographic images. A method for generating holographic images is also provided.

In described examples, a system (e.g., a projection system) can include a diffractive optical element adapted to be illuminated by at least one coherent light beam. A lens array is coupled to receive a diffracted beam of light from the diffractive optical element. The lens array includes a first and a second array lens. The first array lens is coupled to receive a first sector of a pattern of illumination of the diffracted beam of light, and the second array lens is coupled to receive a second sector of the pattern of illumination of the diffracted beam of light. A spatial light modulator is coupled to receive overlapping diffracted beams of light from the first and second array lenses to form an image beam.

A projection system arranged to receive an image for projection. The image is a colour image comprising a first colour component and a second colour component. The system is arranged to calculate a first hologram of the first colour component and a second hologram of the second colour component. The system is further arranged to add content of the second colour component to the first colour component before calculating the first hologram. The first hologram contains information of the first colour component and information of at least a portion of the second colour component. The system is further arranged to form a first holographic reconstruction by illuminating the first hologram with first colour light and to form a second holographic reconstruction by illuminating the second hologram with second colour light. The first holographic reconstruction changes the chromaticity of the at least a portion of the second colour component.

A display system and a method of adjusting a display system are disclosed. A first plurality of pixels is arranged to display a first hologram, receive light of a first wavelength, and output spatially-modulated light according to the first hologram, along a first optical path. A first Fourier transform lens on the first optical path forms a first holographic reconstruction at a replay plane. A second plurality of pixels is arranged to display a second hologram, receive light of a second wavelength, and output spatially modulated light according to the second hologram, along a second optical path. A second Fourier transform lens on the second optical path forms a second holographic reconstruction at the replay plane. A first optical element on the first optical path is arranged to receive the output light from a first part of the first optical path and direct it along a second part of the first optical path to the replay plane. A second optical element on the second optical path is arranged to receive the output light of the second wavelength from a first part of the second optical path and direct it along a second part of the second optical path to the replay plane. The length of the first part of the first optical path is not equal to the length of the first part of the second optical path. The first part of the first optical path may he substantially collinear with the first part of the second optical path.

A spatial light modulating panel using a transitive liquid crystal display panel and a three-dimensional display device using the same. A a spatial light modulator including a plurality of pixels arrayed in a matrix manner; and a liquid crystal layer configured to modulate phase of an incident light passing through the each pixel, respectively. The spatial light modulator and the 3D display using the same provides a thin flat type display system having an easy and simple structure and a low manufacturing cost.

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).