A projection apparatus, adapted to project a virtual image to a projection target, and comprising a light source module, a light modulator, an optical lens and an optical film is provided. The light source module provides a light beam. The light modulator adjusts a transmission direction of the light beam. The light modulator modulates the light beam according to an input signal to generate the virtual image. The optical lens has a front view direction on a reference plane. The projection target receives an environment beam in the front view direction to form an environment image. The optical film projects the virtual image to the projection target along a projection direction. The front view direction and the projection direction have an included angle on the reference plane. Moreover, an image projection method is also provided.

An apparatus and method for processing a holographic image are disclosed. The apparatus calculates a first calculation result with respect to an image for the left eye and a first calculation result with respect to an image for the right eye and stores the results at different memory addresses of a storage. Thereafter, the apparatus calculates values of a waveform of light to be modulated by a spatial light modulator by performing a second calculation that uses all of the first calculation results stored in the storage. An image window of the image for the left eye and an image window of the image for the right eye are spatially separated from each other by the apparatus in a viewing window of a hologram image reproduced via the spatial light modulator.

The present invention provides a light-guiding plate which is applicable to incident rays over a wide ray angular range and wide wavelength rage, and is able to suppress a decrease in optical efficiency. A light-guiding plate 200 having a light diffracting portion 1200 for diffracting incident light by a multiple-recorded hologram is configured such that, in the light diffracting portion, when light 1210 of a single wavelength having a certain angular range is incident, at least two or more outgoing rays 1220 are discretely emitted with a first angular space θs, and the emitted rays each have a second angular range θa, and the first angular space θs is equal to or larger than the second angular range θa.

An electronic device may include an optical system that redirects light from a display module towards an eye box along an optical path. The optical path may include a holographic coupler and a resolution-enhancing holographic element. The holographic element may include a first set of holograms and the coupler may include a second set of holograms. The first set of holograms may be characterized by a first set of selectivity curves having first primary lobes. The second set of holograms may be characterized by a second set of selectivity curves having second primary lobes that overlap the first primary lobes. This may configure the holographic element to narrow the second selectivity curves by diffracting some of the light out of the optical path, thereby optimizing the resolution of images in the light provided to the eye box.

A system is provided. The system includes a light source configured to emit an infrared light to illuminate an eye of a user. The system includes a grating disposed facing the eye and including a birefringent material film configured with a uniform birefringence lower than or equal to 0.1. The grating is configured to diffract the infrared light reflected from the eye, and transmit a visible light from a real world environment toward the eye, with a diffraction efficiency less than a predetermined threshold. The system includes an optical sensor configured to receive the diffracted infrared light and generate an image of the eye based on the diffracted infrared light.

An optical system includes an optical lens, a polarization volume hologram (PVH) layer arranged over the optical lens, and an IR absorbing structure arranged between the optical lens and the PVH layer. The PVH layer being configured to reflect infrared (IR) light. The IR absorbing structure includes a quarter-wave plate (QWP) arranged between the optical lens and the PVH layer and a linear absorptive polarizer arranged between the QWP and the optical lens. The linear absorptive polarizer is configured to absorb IR light.

Provided is an augmented reality device. The augmented reality device includes a first projection assembly and a first display assembly. The first display assembly is disposed on a light exit side of the first projection assembly. The first projection assembly includes a first scanner, a first laser, and a first lens group. The first display assembly includes a first holographic diffraction grating and a first lens. An exposure device is also provided.

An optical element is configured to be worn in front of an eye of a wearer. The optical element has two main surfaces and includes at least one holographic diffusive element having diffusive properties resulting from spatial variations of refractive index of said holographic diffusive element. The spatial variation of refractive index is greater than 0.001 at at least one given wavelength, on a distance less than 30 μm. An optical equipment includes the optical element and methods for recording a holographic medium onto an optical lens.

A method of displaying a Computer Generated Holographic (CGH) image by a display, including setting pixel values of a Spatial Light Modulator (SLM) included in a Head Mounted Display (HMD), producing a interference based holographic image at a first location by projecting coherent light onto the SLM, and re-imaging the holographic image from the first location to form a holographic image in front of an eye of a viewer wearing the HMD. Related apparatus and methods are also described.

A light projection apparatus is provided comprising: a source of light; a switchable grating on a first substrate; and a diffractive optical element. Light is diffracted at least once by the switchable grating and is diffracted at least once by the DOE.