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
  • G02B27/0101—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
  • G02B5/00—Optical elements other than lenses
  • G02B5/02—Diffusing elements; Afocal elements
  • G02B5/0273—Diffusing elements; Afocal elements characterized by the use
  • G02B5/0284—Diffusing elements; Afocal elements characterized by the use used in reflection
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B21/00—Projectors or projection-type viewers; Accessories therefor
  • G03B21/13—Projectors for producing special effects at the edges of picture, e.g. blurring
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B21/00—Projectors or projection-type viewers; Accessories therefor
  • G03B21/54—Accessories
  • G03B21/56—Projection screens
  • G03B21/60—Projection screens characterised by the nature of the surface
  • G03B21/62—Translucent screens
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B21/00—Projectors or projection-type viewers; Accessories therefor
  • G03B21/54—Accessories
  • G03B21/56—Projection screens
  • G03B21/60—Projection screens characterised by the nature of the surface
  • G03B21/62—Translucent screens
  • G03B21/625—Lenticular translucent screens
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
  • G03B29/00—Combinations of cameras, projectors or photographic printing apparatus with non-photographic non-optical apparatus, e.g. clocks or weapons; Cameras having the shape of other objects

Definitions

• the present application relates to the display of an image on a windshield of a motor vehicle.
• a disadvantage is that part of the light projected onto the transparent diffuser film is transmitted by this film, passes through the windshield, and is projected outside the vehicle. This is problematic in some applications.
• this makes the existing systems incompatible with certain vehicles, for example military, in which, for reasons of confidentiality, it is not acceptable that the information projected in the occupants of the vehicle can be read from outside the vehicle.
• this makes existing systems incompatible with certain stealth vehicles, in which light transmitted through the transparent diffuser film and the windshield could make the vehicle easily detectable.
• an embodiment provides a system for displaying an image on a vehicle windshield comprising: a stack of first and second films at least partially covering one side of the windshield, the first film being disposed between the windshield and the second film; and a projector adapted to project an image on the face of the second film opposite to the windshield, wherein: the second film is a reflective diffuser screen or a photoluminescent film adapted to display said image in a first visible wavelength range ; and the first film is a reflector adapted to reflect at least 50% and preferably at least 90% of the light transmitted by the second film towards the windshield in said first wavelength range.
• the first and second films are transparent for the light coming from the windshield.
• the second film is a reflective diffuser screen, and the projector transmits only in said first wavelength range.
• the second film is a suitable photoluminescent film, when it is excited by rays with at least one activation wavelength located outside the first range of wavelengths, to emit the light only in said first wavelength range, and wherein the projector is adapted to emit at said at least one activation wavelength.
• the first film is a holographic film.
• the first film is responsive only to the wavelengths of said first wavelength range, and is transparent to other wavelengths.
• said first range of wavelengths has a spectral width of less than 50 nm.
• the windshield is a shielded windshield.
• the projector is a laser projector.
• the system further comprises a blur element disposed between the projector and the second film.
• the blur element is a permanent diffuser arranged to intercept only a portion of a beam projected by the projector on the second film.
• the blur element is an electrically activatable and deactivatable diffuser arranged to intercept all of a beam projected by the projector onto the second film.
• Figure 1 is a schematic sectional view illustrating an embodiment of a system for displaying an image on a windshield
• Figure 2 is a schematic sectional view illustrating another embodiment of a system for displaying an image on a windshield
• Figure 3 is a schematic sectional view illustrating an alternative embodiment of a system for displaying an image on a windshield
• FIG. 4 very schematically represents an example of an image that can be displayed on a windshield by the system of FIG. 3;
• Figure 5 is a schematic sectional view illustrating another alternative embodiment of a system for displaying an image on a windshield.
• Figure 1 is a schematic sectional view illustrating an example of an embodiment of a system 100 for displaying an image on a transparent windshield 102.
• the system 100 comprises an assembly comprising the windshield 102 itself, and a stack of two films 104 and 106 coating the inner face of the windshield 102, that is to say the face of the windshield -brise 102 turned towards the interior of the vehicle.
• the film 104 is located between the windshield 102 and the film 106.
• the film 104 is adhered to the inside face of the windshield 102 and the film 106 is glued to the face of the film 104 opposite the windshield. 102.
• the stack consisting of the films 104 and 106 covers substantially the entire surface of the film. windshield 102.
• the embodiments described are not however limited to this particular case.
• the windshield 102 may have a monolayer structure or a multilayer structure. It can include glass, polycarbonate, or any other transparent material that can be used to make a windshield.
• the windshield 102 is an armored windshield made of laminated glass approximately 2 to 12 cm thick, consisting of a stack of several layers of glass separated in pairs by polyvinyl interlayers. of butyral (PVB). Viewed from the front, the windshield 102 has for example a rectangular shape.
• the system 100 further comprises a projector 108 located inside the vehicle and arranged to project an image on all or part of the surface of the film 106 opposite to the windshield 102 (that is to say facing towards inside the vehicle).
• the projector 108 is preferably a projector for displaying information with a relatively high luminance (in particular to obtain good visibility even in daylight), and relatively small areas (so as not to interfere with the vision of the outdoor scene).
• the projector 108 comprises, for example, a laser source coupled to a vector scanning device, or an active matrix based on light-emitting diodes coupled to a projection optical system, or one or more light-emitting diodes coupled to a focusing optical system and to a light-emitting diode. vector scanning device.
• the projector 108 emits in a relatively narrow wavelength range, for example having a spectral width of less than 50 nm.
• the film 106 is a reflective diffuser film adapted to reflect, by diffusing more or less strongly, the light from the projector 108, and not altering the light from the pare -brise 102 (that is to say from outside the vehicle).
• the film 106 thus forms a transparent display screen for the light from outside the vehicle.
• the film 106 may be monolayer or multilayer.
• the film 106 may include a transparent layer having one face with micro ⁇ structuring, for example lenticular, whose shape is adapted to only diffuse the light reflected by this face, without altering the transmitted light.
• the micro ⁇ structures can be coated with a thin semi-transparent metal layer promoting the reflection of light from inside the vehicle while allowing most of the light coming from outside.
• transparent reflective diffuser films may be used, for example films of the type marketed by LUMINIT under the name “Light Shaping Diffuser”, films of the type described in the article entitled “Microstructured head-up display screen for automotive applications “by Hedili et al, holographic diffuser films, etc.
• the film 104 is a reflective film adapted to reflect the majority (at least 50%), and preferably all or almost all (at least 90%) of the light from the projector 108 and transmitted by the film 106, without significantly altering light from outside the vehicle.
• the film 104 is adapted to reflect at least half and preferably at least 90% of the light power transmitted by the film 106 to the emission wavelengths of the projector 108.
• the film 104 thus forms a transparent reflector for light coming from the outside.
• the film 104 is for example a holographic film comprising a network of Bragg mirrors adapted to reflect all or almost all the light coming from inside the wavelength vehicle emitted by the projector 108.
• the holographic film 104 is preferably non-responsive to wavelengths other than those emitted by the projector 108, i.e., it is substantially transparent in the two directions for these wavelengths.
• the light from the outside of the vehicle at the wavelengths at which the film 104 is reactive may be slightly attenuated by the film 104, but is not deformed or completely stopped by the film 104.
• light from outside is preferably chosen a projector 108 and a corresponding film 104 operating at wavelengths little or not present in the outdoor scene.
• a projector 108 and a corresponding film 104 are preferably chosen to operate only in a narrow band of wavelengths, for example a spectral band of width at half height less than 50 nm.
• the projector 108 is a monochromatic laser projector, and the film 104 is active only at the emission wavelength of the projector 108.
• the film 104 does not alter, or only in negligible proportions, the information from the outside.
• films adapted to reflect all or almost all the light coming from inside the vehicle at the wavelengths emitted by the projector 108, without altering the information coming from the outside, can be used, for example a non-holographic film comprising a network of Bragg mirrors.
• Fig. 2 is a schematic sectional view illustrating an example of another embodiment of a system 200 for displaying an image on a transparent windshield 102.
• the system 200 comprises an assembly including the windshield 102 itself, which may be identical or similar to that of the system 100 of FIG. 1, and a stack of two films 204 and 206 coating the inner face of the windshield 102, the film 204 being located between the windshield 102 and the film 206.
• the film 204 is stuck on the inside of the windshield breeze 102 and the film 206 is stuck on the face of the film 204 opposite the windshield 102.
• the stack constituted by the films 204 and 206 substantially covers the entire surface of the windshield 102. The modes described embodiments are not limited to this particular case.
• the system 200 further comprises a projector 208 located inside the vehicle and arranged to project an image on all or part of the surface of the film 206 opposite to the windshield 102 (that is to say facing towards inside the vehicle).
• the projector 208 comprises for example a laser source coupled to a vector scanning device, or one or more light emitting diodes coupled to a focusing optical system and a vector scanning device.
• the projector 108 emits in a relatively narrow wavelength range, for example having a spectral width of less than 50 nm.
• the film 206 is a transparent photoluminescent film, that is, a transparent film having photo luminescent nanoparticles ⁇ adapted to emit light at a visible wavelength specific, called the emission wavelength, when excited by rays at another specific wavelength, called the activation wavelength.
• the light emitted by the film 206 may be monochromatic, for example red, green or blue.
• the activation wavelength of the film 206 is preferably located outside the visible spectrum, for example in the ultraviolet.
• the film 206 is a film of the type marketed by SUN Innovations under the trade name "TRANSPLAY", activatable by radii of approximately 405 nm wavelength, and emitting red light when it is activated.
• the projector 208 is adapted to emit at the activation wavelength of the film 206.
• the projector 208 projects onto the film 206 an image at the activation wavelength of the film.
• the photons emitted by the projector 208 are absorbed by the film 206 which, in turn, emits photons at its emission wavelength. This causes the film 206 to display, at the emission wavelength of the film, the image (possibly invisible) projected by the projector 208 at the activation wavelength of the film.
• the film 206 is transparent. It does not alter information from outside the vehicle. The film 206 thus forms a transparent display screen for the light coming from outside the vehicle.
• the film 206 may comprise a plurality of superimposed transparent photoluminescent films, emitting at different wavelengths and activatable by different wavelengths.
• the projector 208 is then chosen to be able to emit at different activation wavelengths of the film.
• the projector 208 illuminates the film 206, a portion of the visible light generated by the film is emitted toward the film 204, i.e. towards the outside of the vehicle.
• the film 204 is a reflective film adapted to reflect the majority (at least 50%), and preferably all or almost all (at least 90%) of the light emitted by the film 206 towards the outside of the vehicle, without altering the light coming from outside the vehicle.
• the film 204 is adapted to reflect at least half and preferably at least 90% of the light power from the film 206 at the emission wavelengths of the film 206.
• the film 204 thus forms a transparent reflector for the light coming from the outside.
• the film 204 is for example a holographic film adapted to reflect all or almost all of the light coming from the inside of the vehicle at the emission wavelengths of the film 206.
• the holographic film 204 is preferably nonreactive at wavelengths other than the emission wavelengths of film 206, i.e., it is substantially transparent in both directions for these wavelengths.
• the light from the outside of the vehicle at the wavelengths at which the film 204 is reactive may be slightly attenuated by the film 204, but is not deformed or completely stopped by the film 204.
• the film 204 light coming from the outside of the vehicle, is preferably chosen a film 206 and a corresponding film 204 active only at wavelengths little or no present in the outdoor scene.
• a corresponding film 206 and film 204 are preferably selected which are active only in a narrow range of wavelengths, for example a spectral band with a half-height width of less than 50 nm.
• the film 204 does not alter, or only in negligible proportions, the information coming from the outside.
• films adapted to reflect all or almost all the light coming from the inside of the vehicle at the wavelengths emitted by the film 206, without altering the information coming from the outside, can be used, for example a non-holographic film comprising a network of Bragg mirrors.
• An advantage of the embodiments described with reference to FIGS. 1 and 2 is that they make it possible to display, on a windshield of a motor vehicle, information intended for an occupant of the vehicle, without the light used to display this information is not detectable outside the vehicle, and without the information from outside the vehicle is tampered with.
• the projectors 108 and 208 of the embodiments of Figures 1 and 2 are of preferably vector-type scanning projectors.
• vector-scan projectors are well suited for displaying sharp-edged patterns, they are generally unsuitable for displaying blurred-edge patterns.
• sharp edge patterns can be displayed in peripheral areas of the windshield to provide information such as vehicle speed, position, etc.
• Blurred edge patterns may for example be used in a central area of the windshield in augmented reality applications.
• it can be provided display on the windshield a pattern with fuzzy edges superimposed on this real element, so as to obtain a highlighting or zoning effect of the real element.
• FIG. 3 is a diagrammatic sectional view illustrating an example of an alternative embodiment of a system for displaying an image on a windshield, enabling the display of an image comprising both sharp edges and blurred edges patterns.
• the display system 300 of FIG. 3 comprises the same elements as the display system 100 of FIG. 1.
• the projector 108 is for example a vector-type scanning projector.
• the system 300 further comprises, between the projector 108 and the film 106, a transmissive diffuser 301, that is to say a sheet, plate or film, transmitting towards its side facing the film 106, the light illuminating its face turned towards the projector 108, diffusing more or less strongly this light.
• the diffuser 301 is arranged to intercept a portion, but not all, of the beam of light rays emitted by the projector 108 towards the film 106.
• a portion 106a of the film 106 receives rays emitted by the projector 108 and passing through the diffuser 301
• a portion 106b of the film 106 receives rays emitted by the projector 108 and not passing through the diffuser 301.
• the diffuser 301 thus forms a blur element for transforming patterns with sharp edges generated by the projector 108 in patterns with fuzzy edges.
• the area 106a of the film 106 may display fuzzy edge patterns
• the area 106b of the film 106 may display sharp edge patterns.
• FIG. 4 is a front view of the film 106, very schematically showing an example of an image that can be displayed by the system of FIG. 3.
• the diffuser 301 is arranged so that the portions 106a and 106b of the film 106 are in the form of contiguous parallel rectangular strips, occupying respectively an upper portion and a lower portion of the pare -brise 102 (in the orientation of the figures). In the example shown, the portion 106b occupies most of the windshield 102.
• the embodiments described are not limited to this particular arrangement of the diffuser 301.
• the diffuser 301 can be arranged that the portion 106a of the film 106 has the shape of a rectangular ring occupying a peripheral region of the windshield 102, and that the portion 106b has the shape of a rectangle occupying the central part of the windshield.
• Other provisions of the diffuser 301 can of course be considered.
• FIG. 4 shows, on the portion 106a of the film 106, fuzzy spots 401 corresponding to patterns with sharp edges generated by the projector 108 and blurred by the diffuser 301, and on the portion 106b of the film 106, sharp-edged pictograms 403 corresponding to patterns generated by the projector 108 in a portion of the projection beam not passing through the diffuser 301.
• FIG. 5 is a diagrammatic sectional view illustrating an example of another variant embodiment of a system for displaying an image on a windshield, enabling the display of an image comprising both patterns sharp edges and blurred edge patterns.
• the display system 500 of FIG. 5 comprises the same elements as the display system 100 of FIG. 1.
• the projector 108 is for example a vector scanning projector.
• the system 500 further comprises, between the projector 108 and the film 106, an electrically activatable / deactivatable transmitting diffuser 501, for example a liquid crystal diffuser of the PDLC type, of the English "Polymer Dispersed Liquid Crystal” - crystals dispersed in a polymer.
• the diffuser 501 transmits, by diffusing it, the light illuminating its face turned towards the projector 108, when it is activated by means of a suitable electrical control signal, and transmits the light without diffusing it when 'it is off.
• the diffuser 501 thus forms an electrically activatable / deactivatable blur element, making it possible to transform patterns with sharp edges generated by the projector 108 into patterns with fuzzy edges.
• the diffuser 501 is arranged to intercept the entire beam of light rays emitted by the projector 108 towards the film 106.
• To display both sharp-edged patterns and patterns with fuzzy edges on the film 106 it is possible to project an alternation of frames with patterns that are to be shown net, and frames with patterns that we want to blur.
• the diffuser 501 can be deactivated, and whenever a frame with patterns that one wishes to make appear blurry is projected, the diffuser 501 can be activated.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Instrument Panels (AREA)

Applications Claiming Priority (2)

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• 2013
  • 2013-11-18 FR FR1361286A patent/FR3013462B1/fr active Active
• 2014
  • 2014-11-04 EP EP14806004.9A patent/EP3072007A1/de not_active Withdrawn
  • 2014-11-04 US US15/033,977 patent/US20160266385A1/en not_active Abandoned
  • 2014-11-04 WO PCT/FR2014/052804 patent/WO2015071572A1/fr not_active Ceased

Non-Patent Citations (1)

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