Abstract: A waveguide type display apparatus is provided. This waveguide type display apparatus includes a waveguide through which an image proceeds and a leakage image reducer configured to reduce emission of a leakage image leaked from the waveguide without total internal reflection in the waveguide, from among images, to the outside by a volume grating.

Abstract: A holographic lens and a display apparatus using the same as a combiner, the holographic lens including a phase profile obtained through an optimization process for each position to form an imaging optical system for forming a virtual image of lights emitted from a plurality of areas.

Abstract: A display device includes a light source array including a plurality of light sources where at least one of the plurality of light sources is selectively driven, a spatial light modulator for modulating light from the light source array to form image light, a focusing optical system for focusing the image light formed by the spatial light modulator at a position in a predetermined eye box, a micro mirror array arranged in an optical path formed in the focusing optical system and including a plurality of mirror cells. The plurality of mirror cells are controlled to be in an ON state in that light is reflected in a direction toward an inside of the eye box or to be in an OFF state in that light is reflected in a direction toward an outside of the eye box.

Abstract: A display device includes a display element configured to output light to display an image, a waveguide including a first surface to which the light is incident and a second surface opposite the first surface, an input coupler provided in the waveguide to input the light into the waveguide, a telecentric assembly configured to cause incident angles of light beams incident to the input coupler to be the same as each other, and an output coupler configured to output light propagating in the waveguide to outside of the waveguide.

Abstract: A display apparatus including a volume grating-based combiner is disclosed. The display apparatus includes: an image providing device; and a combiner, wherein the combiner includes a plurality of volume gratings configured to diffract light containing an image, which is emitted from the image providing device, each volume grating has a first surface and a second surface facing each other, and each volume grating is further configured to diffract light incident on the first surface and transmit therethrough light incident on the second surface without diffraction.

Abstract: A display device including a meta surface is provided. The display device includes an image provider comprising a spatial light modulator configured to modulate light according to image information, wherein the image provider is configured to provide the light comprising the image information; an optical element configured to focus the light from the image provider; and a meta surface deflector positioned between the image provider and the optical element to deflect the light, and change a deflection direction of the light according to a polarization of the light so that a first position of the light of a first polarization focused by the optical element is different than a second position of the light of a second polarization orthogonal to the first polarization focused by the optical element.

Abstract: A hologram profile optimization method includes: setting a first hologram profile as a variable; and performing an optimization cycle a predetermined number of times, wherein the optimization cycle includes encoding the first hologram profile into a binary hologram profile by using an ApproxSign function; calculating a field value of a holographic image on a display surface for the binary hologram profile, considering high-order diffraction term noise of the holographic image by using a tiling function; calculating an intensity of the holographic image on the display surface; calculating a loss function value based on a difference between the intensity of the holographic image and an intensity of a target image; and updating the first hologram profile to a second hologram profile based on the loss function value.

Abstract: A retinal projection display device is provided. The retinal projection display device includes a light source configured to emit light, a spatial light modulator configured to generate diffracted light by diffracting the emitted light, a holographic optical element configured to reflect the diffracted light by duplicating the diffracted light into a plurality of complex wavefronts, and a field lens configured to focus the plurality of complex wavefronts to a plurality of respective focal points in an eye-box, wherein the plurality of complex wavefronts overlap each other.

Abstract: Provided is a multi-image display apparatus including an image forming device configured to form a first image, a first polarization plate configured to transmit a first polarization component of the first image provided from the image forming device, a second polarization plate configured to transmit a second polarization component of a second image that is provided from a path different from the first image, the second polarization component being different from the first polarization component, a screen configured to reflect and diffuse the first image, and transmit the second image, and a polarization selective lens configured to focus the first image having the first polarization component, and transmit the second image having the second polarization component without refraction.

Abstract: An image processing method and apparatus include: obtaining a plurality of input optical images and a plurality of output optical images for a near-eye display apparatus; training a neural network for modeling the waveguide optical system by using a training set including the obtained input and output optical images; and obtaining a uniformity correction image to be input to the trained neural network such that the trained neural network then outputs a target uniformity image having certain brightness uniformity.

Abstract: An optical apparatus and a near-eye display apparatus including the same are provided. The optical apparatus includes a display panel configured to form an image, a first polarization rotator configured to electrically control a light emitted from the display panel to have a first polarization state, a first ¼ wave plate configured to convert the first polarization state of a light transmitted from the first polarization rotator to a second polarization state, and an optical element group configured to display a first image having a first viewing angle and a second image having a second viewing angle that is greater than the first viewing angle based on the second polarization state of a light transmitted from the first ¼ wave plate.

Abstract: A multi-image display apparatus includes a light source configured to emit a first wavelength light, a second wavelength light, and a third wavelength light, a spatial light modulator configured to modulate the first wavelength light, the second wavelength light, and the third wavelength light to form a first image including a first color holographic image, a second color holographic image, and a third color holographic image, a polarization selective lens configured to focus the first image having only a first polarization component and transmit a second image having only a second polarization component without refraction, the second image being provided to the polarization selective lens along a different path from the first image, wherein chromatic aberration of the polarization selective lens is offset by adjusting a depth of the first color holographic image, the second color holographic image, and the third color holographic image.

Abstract: Provided is a display apparatus including an image generator configured to time-sequentially generate a plurality of images by modulating light, and an optical system including a freeform surface that is configured to time-sequentially form a plurality of virtual images respectively corresponding to the plurality of images at different depths from a user's eye, wherein each error value among error values between the plurality of images and the plurality of virtual images respectively corresponding to the plurality of images on the freeform surface is less than or equal to a profile value of the freeform surface.

Abstract: A display apparatus includes a waveguide; an input coupler on the waveguide and configured to introduce light containing an image into the waveguide; and an output coupler on the waveguide and configured to output light traveling in the waveguide to the outside of the waveguide, wherein the output coupler includes a plurality of first diffraction grating elements arranged apart from each other and configured to diffract a first light portion in a first wavelength band among the light traveling in the waveguide.

Abstract: Provided are a waveguide optical device and a near-eye display apparatus including the same. The waveguide optical device includes a waveguide that propagates light, an input coupler that inputs the light into the waveguide, and an output coupler that outputs the light propagating in the waveguide to the outside, wherein the output coupler includes a plurality of grating regions, which are arranged to be spaced apart from each other.

Abstract: A holographic display apparatus including a freeform curved surface and an operating method of the holographic display apparatus are provided. The holographic display apparatus includes: an image generator configured to generate a hologram image by modulating light; an optical system including a freeform curved surface for forming the hologram image generated by the image generator in a predetermined depth; and a processor configured to generate a computer-generated hologram (CGH) based on three-dimensional image information by using a phase map including information about an optical aberration with respect to the freeform curved surface and to control the image generator to modulate the light based on the CGH.

Abstract: Provided is a display apparatus including an image generator configured to time-sequentially generate a plurality of images by modulating light, and an optical system including a freeform surface that is configured to time-sequentially form a plurality of virtual images respectively corresponding to the plurality of images at different depths from a user's eye, wherein each error value among error values between the plurality of images and the plurality of virtual images respectively corresponding to the plurality of images on the freeform surface is less than or equal to a profile value of the freeform surface.

Abstract: Provided is a method of generating a hologram, the method including generating a kernel and a neural network configured to model an aberration of a holographic display device, obtaining second image data output from the neural network to which first image data obtained by propagating a first hologram based on the kernel is input, updating the kernel and the neural network based on comparing the second image data and predetermined image data, and generating a second hologram based on the kernel and the neural network.

Abstract: Provided are holographic display systems and methods for generating a hologram by compensating for aberrations of a holographic display device. The holographic display system may include a holographic display device and a hologram generating device. The hologram generating device may generate a hologram by propagating hologram segments, using kernels generated by modeling each aberration corresponding to each of hologram plane segments to compensate for aberrations.

Abstract: Provided is a display apparatus including a combiner having asymmetric magnification. The display apparatus may include: an image forming device configured to form a virtual image; and a combiner configured to mix the virtual image with light containing an outside landscape and provide a viewer with the virtual image and the light that are mixed with each other, wherein the combiner may include a curved surface that varies a size of the virtual image with a first magnification in a first direction and a second magnification in a second direction perpendicular to the first direction, the second magnification being less than the first magnification.