Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/017—Head mounted
  • G02B27/0172—Head mounted characterised by optical features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/0081—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00 with means for altering, e.g. enlarging, the entrance or exit pupil
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K35/00—Instruments specially adapted for vehicles; Arrangement of instruments in or on vehicles
  • B60K35/20—Output arrangements, i.e. from vehicle to user, associated with vehicle functions or specially adapted therefor
  • B60K35/21—Output arrangements, i.e. from vehicle to user, associated with vehicle functions or specially adapted therefor using visual output, e.g. blinking lights or matrix displays
  • B60K35/23—Head-up displays [HUD]
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
  • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
  • G02B26/0808—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more diffracting elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
  • G02B27/0103—Head-up displays characterised by optical features comprising holographic elements
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/42—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect
  • G02B27/4272—Diffraction optics, i.e. systems including a diffractive element being designed for providing a diffractive effect having plural diffractive elements positioned sequentially along the optical path
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
  • G02B6/24—Coupling light guides
  • G02B6/42—Coupling light guides with opto-electronic elements
  • G02B6/4201—Packages, e.g. shape, construction, internal or external details
  • G02B6/4204—Packages, e.g. shape, construction, internal or external details the coupling comprising intermediate optical elements, e.g. lenses, holograms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60K—ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
  • B60K2360/00—Indexing scheme associated with groups B60K35/00 or B60K37/00 relating to details of instruments or dashboards
  • B60K2360/20—Optical features of instruments
  • B60K2360/33—Illumination features
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
  • G02B2027/0123—Head-up displays characterised by optical features comprising devices increasing the field of view
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/0101—Head-up displays characterised by optical features
  • G02B2027/0123—Head-up displays characterised by optical features comprising devices increasing the field of view
  • G02B2027/0125—Field-of-view increase by wavefront division
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/017—Head mounted
  • G02B27/0172—Head mounted characterised by optical features
  • G02B2027/0174—Head mounted characterised by optical features holographic
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
  • G02B27/01—Head-up displays
  • G02B27/017—Head mounted
  • G02B2027/0178—Eyeglass type

Definitions

• the display structure further comprises a diffractive out- coupling structure configured to receive from the exit pupil expansion structure a first diffracted set of beams and a second diffracted set of beams associated with a first diffracted set of k-vectors and a second diffracted set of k-vectors , respectively, lying in the first domain and the second domain, respectively, and the out-coupling structure is configured to couple light from the first diffracted set of beams and light from the second diffracted set of beams out of the waveguide .
• FIG . 1 shows a partial orthographic top view of a display structure
• any drawing of the aforementioned drawings may be not drawn to scale such that any element in said drawing may be drawn with inaccurate proportions with respect to other elements in said drawing in order to emphasize certain structural aspects of the embodiment of said drawing.
• a "vehicular display device” may refer to a display device configured for use in a vehicle , for example , while operating said vehicle . Additionally or alternatively, a vehicular display device may refer to a display device configured to present images and/or data associated with a vehicle and/or operation thereof . Generally, a vehicular display device may or may not be implemented as a vehicle-mounted display device fixed to a vehicle .
• k-space may refer to a framework, wherein spatial frequency space analysis is used to relate k-vectors to geometrical points .
• k-space may refer to a two- dimensional proj ected space associated with a waveguide .
• any diffraction event occurring while light propagates in a waveguide can be represented as a translation .
• the operation of a display structure may be described by the manner in which said display structure causes a set of input k-vectors to move in k-space .
• permitted k-vectors of a given wavelength in an unbounded homogeneous medium define a hollow sphere in k-space with a radius defined by the common wavenumber of the k-vectors . Since the common wavenumber of the k-vectors is proportional to the refractive index of the medium, the radius of the hollow sphere is also proportional to the refractive index of the medium .
• permitted k-vectors of a given wavelength are commonly represented by a solid disk with a radius defined by the common wavenumber of the k-vectors .
• Such representation may be viewed as a proj ection of the previously described hollow sphere onto a plane in k-space corresponding to the plane along which the waveguide extends . Every point within the boundary of the solid disk corresponds to two permitted k-vectors having components perpendicular to the plane opposite to one another .
• the radius of the solid disk is proportional to the refractive index of the waveguide .
• annular domain in k-space defined by the relative complement of such smal ler sol id dis k in such larger solid disk, i . e . , the difference of the larger solid di sk and the smal ler solid dis k may be referred to as a "guided propagation domain" associated with a waveguide . All k-vectors with in-plane components lying within such guided propagation domain of a waveguide may propagate in said waveguide in guided manner .
• the smaller solid disk represents permitted k-vectors in a medium surrounding a waveguide . Since light to be coupled into or out of a waveguide must be able to propagate in such surrounding medium, only k-vectors with in-plane components lying within such smaller solid disk may be coupled into or out of a waveguide . Consequently, the smaller solid disk representing permitted k-vectors in a medium surrounding a waveguide may be referred to as a "coupling domain" associated with said waveguide .
• k-vectors permitted in a waveguide can be depicted in k-space using a two-dimensional k-vector diagram .
• a "k-vector diagram" may refer to a depiction of k-space , wherein guided propagation angles for optical beams propagating in a waveguide are represented by an annular guided propagation domain associated with said waveguide .
• a k-vector diagram may refer to a depiction of k-space , wherein non-guided propagation angles of optical beams propagating in a waveguide are represented by a coupling domain associated with said waveguide .
• the waveguide 1100 may have a refractive index of approximately 2 throughout the visible spectrum .
• a waveguide may have any suitable refractive index with any suitable dispersive properties .
• the waveguide 1100 may be surrounded by air with a refractive index of approximately 1 throughout the visible spectrum . Consequently, light may be guided within the waveguide 1100 between opposite air-glass interfaces . In other embodiments , light may be guided within a waveguide between any suitable interfaces , for example , airglass interfaces .
• a "set of input beams" may refer to a set of optical beams directed to an in-coupling structure and corresponding to an input image . Additionally or alternatively, a set of input beams may refer to a set of optical beams propagating towards an in-coupling structure of a display structure from a solid angle defining a field of view of said display structure . Additionally of alternatively, a set of input beams may refer to a set of optical beams associated with a set of input k-vectors lying in a coupling domain associated with a waveguide .
• a “first domain” may refer to a domain in k-space situated within a guided propagation domain associated with a waveguide . Additionally or alternatively, a first domain may refer to a domain in k-space defined by a set of in-coupled k-vectors coupled into a waveguide by an in-coupling structure .
• a domain in k-space def ined by a set of in-coupled k-vectors may refer to a smallest non-empty connected open set within a guided propagation domain associated with a waveguide comprising each of the points representing said set of incoupled k-vectors .
• the display structure 1000 further comprises a diffractive exit pupil expansion structure 1300 .
• a structure being "diffractive” may refer to said structure compri sing a diffractive optical element .
• a diffractive optical element may refer to an optical element the operation of which is based on diffraction of light .
• a diffractive optical element may comprise structural features with at least one dimension of the order of the wavelengths of visible light , for example , at least one dimension less than one micrometer .
• Typical examples of diffractive optical elements include diffraction gratings , e . g .
• one- and two-dimensional diffraction gratings which may be implemented as single-region diffraction gratings or as multi-region diffraction gratings .
• Diffraction gratings may generally be implemented, at least , as surface relief diffraction gratings or volume holographic diffraction gratings , and they may be configured to function as transmission- and/or reflection-type diffraction gratings .
• exit pupil expansion may refer to a process of distributing light within a waveguide in a controlled manner so as to expand the portion of said waveguide wherefrom out-coupling of light occurs .
• exit pupil expansion may be accomplished in waveguide-based display structure using so-called “pupil replication” schemes , wherein a plurality of exit sub-pupils are formed in an imaging system .
• an “exit pupil expansion structure” may refer to a structure suitable or configured for exit pupil expansion, for example , by pupil replication .
• one of a first domain and a second domain may be arranged at a first radial distance from an origin of a k-vector diagram associated with a waveguide , and the other of said first domain and said second domain may be arranged at a second radial distance different to , i . e . , greater or less than, said first radial distance from said origin .
• the out-coupling structure 1400 of the embodiment of FIGs . 1 to 3 is configured to receive from the exit pupil expansion structure 1300 a first diffracted set of beams 1041 and a second diffracted set of beams 1042 .
• a first diffracted set of beams may refer to a set of beams comprising light from a set of in-coupled beams and/or light from a secondary set of in-coupled beams coupled into a waveguide by an in-coupling structure .
• the out-coupling structure 1400 is further configured to couple light from the first diffracted set of beams 1041 and light from the second diffracted set of beams 1042 out of the waveguide 1100 .
• an out-coupling structure being configured to outcouple light both from a first diffracted set of beams associated with a first diffracted set of k-vectors lying in a first domain in k-space and from a second diffracted set of beams associated with a second dif fracted set of k-vectors lying in a second domain disj oint with said first domain may reduce optical losses related to exit pupil expansion .
• an exit pupil expansion structure being configured to diffract a set of in-coupled beams by zeroth-order and first-order diffractions to form a first set of guided beams and a second set of guided beams may further facilitate reducing optical losses related to exit pupil expansion .
• a domain in k-space situated within a guided propagation domain associated with a waveguide "defining a light guiding direction” may refer to said waveguide extending laterally along a plane and said domain comprising a characteristic point , e . g . , centroid of said domain, defining said light guiding direction along said plane .
• the out-coupling structure 1400 comprises a two-dimensional out-coupling grating 1410 having a first periodicity for coupling light from the first diffracted set of beams 1041 out of the waveguide 1100 , a second periodicity for coupling light from the second diffracted set of beams 1042 out of the waveguide 1100 , and a third periodicity for forming the first additional set of beams 1043 and the second additional set of beams 1044 .
• out-coupling structure comprising a two-dimensional out-coupling grating having a first periodicity for coupling light from a first diffracted set of beams out of a waveguide , a second periodicity for coupling light from a second diffracted set of beams out of said waveguide , and a third periodicity for forming a first additional set of beams and/or a second additional set of beams may enable forming an out-coupling structure with single-sided fabrication methods .
• the out-coupl ing structure 1400 is configured to diffract the first diffracted set of beams 1041 and the second diffracted set of beams 1042 to form the first additional set of beams 1043 and the second additional set of beams 1044 , respectively, by first-order diffraction (G° c , — G° c ) .
• an out-coupling structure may or may not be configured to diffract a first diffracted set of beams and a second diffracted set of beams to form a first additional set of beams and a second additional set of beams , respectively, by first-order diffraction . As indicated schematically in FIG .
• the diffraction of the secondary set of in-coupled beams 1022 by the exit pupil expansion structure 1300 could be represented by the inverse of G EPE , i . e . , — G EPE . Consequently, the exit pupil expansion structure 1300 is configured to diffract the secondary set of in-coupled beams 1022 by first-order diffraction ( — G EPE ) to form the first secondary set of guided beams 1033 and by zeroth-order diffraction to form the second secondary set of guided beams 1034 .
• the in-coupl ing structure 1200 comprises an in-coupling grating 1210 for coupling the set of input beams 1020 into the waveguide 1100 .
• an in-coupling structure may or may not comprise such in-coupling grating .
• an in-coupling structure may comprise one or more reflective optical elements , such as mirrors , and/or one or more refractive optical elements , such as pri sms , in addition to or as an alternative to an in-coupling grating .
• the in-coupling grating 1210 of the embodiment of FIGs are examples of the embodiment of FIGs .
• an in-coupling structure comprising a two-dimensional in-coupling grating for coupling a set of input beams into a waveguide as a set of in-coupled beams and as a secondary set of in-coupled beams may faci litate reducing spatial image brightness variations throughout an out-coupling structure .
• the in-coupling structure 1200 is configured to diffract the set of input beams 1020 by first-order diffraction ) to form the set of in-coupled beams 1021 and the secondary set of in-coupled beams 1022 .
• an incoupling structure may or may not be configured to diffract a set of input beams by first-order diffraction to form a set of in-coupled beams and/or a secondary set of in-coupled beams .
• the in-coupling grating 1210 , the exit pupil expansion grating 1310 , and the out-coupling grating 1410 are arranged symmetrically with respect a fictitious transverse plane 1003 extending along to a thickness direction of the waveguide 1100 .
• the transverse plane 1003 extends perpendicular to the plane of the figure .
• an in-coupling grating, an exit pupil expansion grating, and an out-coupling grating may or may not be arranged symmetrical ly with respect to a transverse plane extending along to a thickness direction of a waveguide .
• Any diffractive optical element ( s ) in the display structure 1000 may be formed at least partly using nanoimprint lithography.
• any suitable fabrication method (s) for example, nanoimprint lithography and/or electron-beam lithography, may be used .
• a "head-mounted display device” may refer to a portable display device configured to be worn on the head, as part of a piece of headgear, and/or on or over the eyes .
• a head-mounted display device may or may not be implemented as a see-through display device and/or as a vehicular display device .
• the display device 4000 comprises a frame 4100 and a display structure 4200 according to the first aspect supported by the frame 4100 .
• the display structure 4200 comprises a waveguide 4210 , an in-coupling structure 4220 , an exit pupil expansion structure 4230 , and an out-coupling structure 4240 .
• display device may or may not comprise a frame for supporting a display structure .
• the display device 4000 further comprises an optical engine 4250 configured to direct light 4251 to be coupled into the waveguide 4210 to the in-coupling structure 4220 .
• an optical engine 4250 configured to direct light 4251 to be coupled into the waveguide 4210 to the in-coupling structure 4220 .
• a display device may or may not comprise such optical engine .
• the vehicle 5000 comprises a vehicular display device 5100 in accordance with the second aspect. Even if not explicitly shown in FIG. 5, the embodiment of FIG. 5 or any part thereof may generally comprise any features and/or elements disclosed with reference to or in conjunction with any of FIGs. 1 to 4.
• the vehicular display device 5100 of the embodiment of FIG. 5 is implemented as a head-up display device.
• a display device may or may not be implemented as a head-up display device.
• a “head-up display device” may refer to a see- through vehicular display device configured to present images and/or data to a steerer, e.g., a driver or a pilot, of a vehicle without requiring said steerer to look away from usual viewpoints thereof.
• a head-up display device may or may not be implemented as a vehicle-mounted display device.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Optical Couplings Of Light Guides (AREA)
• Optical Integrated Circuits (AREA)
• Diffracting Gratings Or Hologram Optical Elements (AREA)

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• 2021
  • 2021-12-07 FI FI20216248A patent/FI131552B1/en active
• 2022
  • 2022-11-01 TW TW111141610A patent/TW202331318A/zh unknown
  • 2022-11-21 KR KR1020247020037A patent/KR20240113916A/ko active Pending
  • 2022-11-21 WO PCT/FI2022/050773 patent/WO2023105115A1/en not_active Ceased
  • 2022-11-21 JP JP2024523424A patent/JP2025500729A/ja active Pending
  • 2022-11-21 CN CN202280080537.6A patent/CN118382827A/zh active Pending
  • 2022-11-21 EP EP22812694.2A patent/EP4445203B1/en active Active
  • 2022-11-21 US US18/716,870 patent/US20250035930A1/en active Pending

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