An imaging apparatus includes an in-coupling diffractive optic directs image-bearing light beams into a planar waveguide, an out-coupling diffractive optic directs the image-bearing light beams from the waveguide toward a viewer eyebox, and a turning diffractive optic directs the image-bearing light beams along the waveguide between the in-coupling and out-coupling diffractive optics. The grating vectors of the in-coupling and out-coupling diffractive optics differ in magnitude and orientation while the grating vectors of all three diffractive optics sum to substantially zero. The turning diffractive optic is further arranged to preserve a desired angular relationship of the propagating image bearing beams within the waveguide.

An exposure device for recording a hologram. The exposure device includes at least one modulation unit, which is designed to generate a modulation beam representing a reference beam and/or an object beam by impressing a modulation representing at least one holographic element of the hologram onto a laser beam. The exposure device also includes at least one reduction unit, which is designed to generate a modified modulation beam using the modulation beam, the modified modulation beam having a smaller beam diameter than the modulation beam. The exposure device further includes at least one objective lens unit, which is designed to direct the modified modulation beam through an immersion medium onto a recording material in order to record the hologram by exposing the recording material to the modified modulation beam.

This application relates to a see-through head-mounted display using recorded substrate-guided holographic continuous lens (SGHCL) and a microdisplay with narrow spectral band source or laser illumination. The high diffraction efficiency of the volume SGHCL creates very high luminance of the virtual image.

A head mounted display (HMD) system employs a holographic element in the optical path of the HMD to direct light to a user's eye. The HMD includes a micro-display, a lightguide, and a holographic element coupled to the lightguide. The holographic element is coupled to a polarization film, and together the element and film reflect and transmit light of different polarities in a specified pattern to assist the lightguide in directing light to the user's eye. For example, the hologram and polarization film can be configured to pass R-polarized light and reflect L-polarized light, thereby directing light from the waveguide along a specified path.

A mirror and information image display assembly (300) for a vehicle, a holographic information image display system (300, 106, 104), a vehicle (100) comprising such an assembly, and a method of providing image information to an occupant of a vehicle are disclosed. The assembly has a reflective layer (302) and an image display means (304, 306), for displaying image information to an occupant of the vehicle. The image display means comprises a hologram (304), and a lighting means comprising a light source (306) for illuminating the hologram.

Provided a backlight unit including a light source and a light guide structure configured to guide the light emitted from the light source, the light guide structure includes a first coupler layer including a first output coupler configured to expand light in a first direction and output the expanded light in the first direction to the outside of the light guide structure, and a first expansion coupler configured to expand the light in a second direction perpendicular to the first direction and provide the expanded light in the second direction to the first output coupler, and a second coupler layer including a second output coupler configured to expand light in the first direction and output the expanded light to the outside of the light guide structure, and a second expansion coupler configured to expand light in the second direction and provide the expanded light to the second output coupler.

Mastering systems and methods of fabricating waveguides and waveguide devices using such mastering systems are described. Mastering systems for fabricating holographic waveguides can include using a master to control the application of energy (e.g. a laser, light, or magnetic beam) onto a liquid crystal substrate to fabricate a holographic waveguide into the liquid crystal substrate. Mastering systems for fabricating holographic waveguides in accordance with embodiments of the invention can include a variety of features. These features include, but are not limited to: chirp for single input beam copy (near i.e. hybrid contact copy), dual chirped gratings (for input and output), zero order grating for transmittance control, alignment reference gratings, 3:1 construction, position adjustment tooling to enable rapid alignment, optimization of lens and window thickness for multiple RKVs simultaneously, and avoidance of other orders and crossover of the diffraction beam.

A backlight device having a light guide, a first holographic optical element and a second holographic element are provided. The light guide plate guides light emitted by a light source towards the first holographic optical element. The first holographic optical element, which has a multi-layered structure, is provided on a first side of the light guide plate and reflects the light according to the wavelength ranges based on the characteristics of the multi-layered structure. The second holographic optical element, which concentrates light reflected by the first holographic optical element onto at least two points is provided on a second side of the light guide plate perpendicular to the first side.

An image guide comprising glass or plastic planar substrate, a first hologram area, a second hologram area, and a third hologram area which are formed on the substrate as surface relief grating, period and direction of diffraction structure of the first, second, and third hologram areas have a relationship which is a sum of grating vectors of the first, second, and third hologram areas becomes zero, depth of diffraction structure on the first hologram area is a uniform in the own hologram area, and depth of diffraction structure on the second or third hologram area is chirped in the own hologram area increases luminance and uniformity of virtual image.

A backlight unit may include: a light source providing coherent light; a light guide plate having a light entrance surface on which light from the light source is incident and a light exit surface through which the light is output; a plurality of diffraction gratings (for example, a first input grating, a second input grating, and a third input grating) that are arranged in different regions of the light guide plate to sequentially diffract the light from the light source such that that the beam width of the light may increase as the light propagates in the light guide plate; and a diffraction grating (for example, an output grating) that diffracts and outputs the light having an increased beam width in a direction toward the outside of the light guide plate.