Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R1/00—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
  • B60R1/10—Front-view mirror arrangements; Periscope arrangements, i.e. optical devices using combinations of mirrors, lenses, prisms or the like ; Other mirror arrangements giving a view from above or under the vehicle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R1/00—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
  • B60R1/005—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles specially adapted for viewing traffic-lights
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60R—VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR
  • B60R1/00—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles
  • B60R1/002—Optical viewing arrangements; Real-time viewing arrangements for drivers or passengers using optical image capturing systems, e.g. cameras or video systems specially adapted for use in or on vehicles specially adapted for covering the peripheral part of the vehicle, e.g. for viewing tyres, bumpers or the like

Definitions

• the present invention relates generally to an optical system for diverting light to enable an observer to obtain an additional or different field of view from that which is normally available from the observation position.
• an observer has a limited field of view because of restrictions in the position which can be adopted by the observer and/or by screening or shrouding necessarily present in the vicinity of the observer's position, for example in the form of machine parts or housings of the observation post.
• a machine operator may have a field of view through a window or observation opening in the housing of a machine to enable him or her effectively to operate the machine in normal conditions.
• the range of movement of the articulated arm can position the bucket at locations which are not visible to the machine operator when seated at the controls in view of the necessarily limited size of the window through which the operator can observe the working of the bucket.
• an optical system for extending the field of view of an observer through an opening comprising a light diverting element or system mounted to or adjacent the opening such that an image observed by an observer through the component is upright.
• the present invention may also be considered to comprise an optical device for extending the field of view of an observer through an opening, comprising an optical component positioned or positionable between the observer and the opening and operable to divert by refraction light transmitted therethrough and to compensate for chromatic aberration introduced upon refraction such that light incident thereon from an angle which would not reach the observer can be diverted towards the observer without substantial degradation of the image thus viewed.
• the said light diverting element or system may comprise or include a refractor carried by a mounting so as to be pivotable about an axis transverse the direction of light arriving at an observer at the said predetermined location from the said field of view whereby to be movable between an operative position to be viewed by an observer, and an inoperative position where it does not obstruct the field of view of the observer through the opening.
• the said axis is located transversely of the said refractor, that is generally parallel to, and, preferably along (or spaced from) one edge of the refractor.
• the refractor is a fresnel refractor, that is one comprising a plurality of elementary refracting surfaces in an array defining a general plane of the refractor.
• One of the problems encountered when using refractors for light-diverting purposes arises from the chromatic aberrations, which are introduced upon refraction. Such aberrations can be compensated, however, according to this aspect of the invention, by the provision of a composite refractor comprising a plurality of refracting elements oppositely orientated with respect to their light-diverting action.
• An optical system in which the refractor comprises two fresnel refractors is particularly convenient although three or more refractor elements in an array may be provided.
• an optical device for extending the field of view of an observer through an opening, comprising a first light-diverting optical component acting to divert light incident thereon through the opening at an angle greater than a critical angle of incidence and to transmit therethrough undeviated light incident thereon through the opening at an angle less than the critical angle, and a second light diverting component acting to divert the diverted light from the first component towards the observer.
• the light-diverter system may comprise a composite reflector system having an even number of reflectors.
• a first reflector of such a reflector system may comprise a plurality of reflector elements in an array, with each element of the array being orientated transversely with respect to the general plane of the array.
• Such an array may be of the type generally described in the applicant's earlier British Patent No. 255 945. The disclosure of which is incorporated herein by reference.
• the second reflector may be pivotally mounted to or adjacent one edge of the said first reflector and, as in the refractor embodiment the reflectors are preferably generally planar in form and mounted in such a way that they can be folded parallel to one another and out of the line of sight of an observer to allow the normal field of view through the opening to be unobstructed when the light- diverter is not deployed.
• the present invention also comprehends an optical system for diverting light to an observer from an obscured location, comprising first and second reflective units pivotally connected together for adjustment of their relative inclination, one of the reflective units comprising a plurality of reflective elements in an array extending parallel to the general plane of the said one reflective unit such that light incident on the said one unit is diverted by reflection as it passes through the unit.
• the reflectors or refractor elements may be convexely or concavely curved.
• the mounting assembly may be such that the relative positions of the first and second reflector are adjustable to obtain a field of view therefrom in different directions in dependence on the relative position of the two elements.
• Figure 1 is a side view of a first embodiment of the invention
• Figure 1 A is an enlarged side view of the light diverter system of Figure 1;
• Figure 2 is a schematic side view of a composite refractor suitable to form part of the embodiment of Figure 1;
• Figure 3 is a similar schematic side view of a tripartite composite refractor suitable to form part of an alternative version of the embodiment of Figure 1;
• Figure 4 is a side view of a second embodiment of the invention in position in a cabin of a vehicle or machine;
• Figure 4A is an enlarged side view of the embodiment of Figure 4:
• Figure 5 is a side view of an alternative embodiment of the invention in an operative position:
• Figure 5A is a side view of the embodiment of Figure 5 in a stowed or "parked" configuration.
• Figure 6 is a side view of an alternative embodiment of the invention utilising reflectors shown in a deployed or operative position;
• Figure 6A is a side view of the embodiment of Figure 4 in a parked or stowed position
• Figure 7 is a side view of a further embodiment of the invention incorporated into a structure
• Figure 8 is a side view of a further alternative embodiment of the invention positioned adjacent an opening in a machine or vehicle;
• Figure 9 is an alternative diagrammatic illustration of a further alternative embodiment suitable for a machine or a vehicle;
• Figure 10 is a further schematic diagram illustrating another alternative embodiment of the invention.
• Figure 1 illustrates a first embodiment of the invention adapted for use in an aircraft such as a sailplane or glider generally indicated 11.
• an aircraft such as a sailplane or glider generally indicated 11.
• Figure 1 only the front upper portion 12 of the aircraft is illustrated, together with the transparent canopy 13. It is known that, particularly when landing, the view forwardly and downwardly in such an aircraft is of critical importance.
• An enlarged field of view is provided by fitting a light diverting optical component 14 to the roof just behind the transparent canopy.
• FIG. 1A comprises a composite fresnel prism structure which may be called a multi element fresnel prism refractor (MEFPR) 14 pivotally connected by a pivot 15 parallel to one edge horizontally and transversely across the canopy 13 so as to be perpendicular to the line of sight of a pilot as indicated by the arrows 16.
• the MEFPR 14 can thus be turned between a use position, as shown in Figure 1, and a stowed or parked position either forwardly against the canopy 13 or rearwardly against the roof 12. Between these two end positions, the MEFPR may be turned to any position to allow the user to select the precise field of view, that is so that the area of MEFPR is filled with light from the direction of interest.
• MEFPR multi element fresnel prism refractor
• the light-diverting optical component 14 in the deployed position, acts to refract light arriving from a forward region below the field of view of the pilot, represented by the ray traces A and B, thereby allowing a view below the nose of the aircraft immediately ahead of it to be obtained from the restricted position of the pilot strapped in the aircraft.
• Shades or louvres 17 (see Figure 1 A) protect against stray light effects and also ensure that the refractor is not working when mounted to its stowed or parked position.
• the refractor is a composite fresnel refractor unit the refractor 20 of which comprises two elements as illustrated in more detail in Figure 2. It will be appreciated that Figure 2 illustrates only a very small part of the fresnel refractor 20, with only two or three elementary prisms of each of two refractor sheets 22, 23 being shown. In practice there would be many more elementary prisms across the width of the element as a whole.
• Each of the refractors 22, 23 which form part of the composite refractor 20 is made of an optically transparent material. Different materials are used for each refractor, in particular materials having different refractive indices from each other.
• the refractor 22 has a plane face 24 and an opposite face having a plurality of inclined elementary surfaces 25 separated by "risers" 26 to form a plurality of adjacent elementary prisms generally indicated 27, 28.
• the refractor element 23, likewise, has a plane face 29, and an opposite face in the form of a plurality of individual elementary surfaces 30, 31 separated by "risers" 32 to define elementary prisms 33, 34.
• a composite refractor suitable for this purpose comprises at least two optical elements of different material from one another positioned with their prismatic apex angles oriented oppositely from one another as illustrated in Figure 2.
• a preferred material for the element 23 is polymethylmethacrylate (PMMA) whilst a preferred material for element 24 is polycarbonate (PC).
• PMMA polymethylmethacrylate
• PC polycarbonate
• the dimensions of the elementary surfaces 25, 31, 30 are typically of the order of 1mm and flat sheets of fresnel refractor may be produced using so-called micro-replication techniques employing thermoplastic material such as PMMA or PC using nanometre precision tooling produced by single point diamond machining.
• the elements 23, 24 may be assembled by bonding together using a transparent adhesive.
• the composite refractor may, of course, be curved in one or more directions to enlarge or reduce the field of view.
• the elementary surfaces 31,32,33 or the corresponding surfaces on the other refractor may be convexly or concavely curved whereby to obtain magnification or reduction of the field of view as appropriate.
• Figure 3 illustrates an alternative composite refractor in which there are three fresnel refractors rather than the two illustrated in Figure 2.
• the refractor 23 has been replaced by two thinner refractors 35, 36 each having inclined elementary surfaces defining prism apex angles in the same direction, both being in the opposite direction from that of the apex angles of the refractor 24.
• This construction allows a shorter path length for the refracted light through each of the optical elements 35, 36 than through the optical element 23 of Figure 2, thereby obtaining improved optical properties.
• This configuration also allows the elements 24,36 to be made exactly the same shape so that they can be fitted together and bonded by a transparent adhesive.
• the element 35 cannot be bonded in this way because the voids between the inclined surfaces and the flat face of element 36 must remain filled with air in order to achieve the desired result, and any adhesive present in these voids would degrade the performance of the component.
• the element 35 may be reversed, so that its flat face is in contact with the flat face of element 36, in which case it can be bonded thereto by transparent adhesive.
• This has the disadvantage that the ribbed face of element 35 faces outwardly and this makes it more difficult to keep clean and dust free.
• the element 35 may be placed, in the same orientation, on the other side of the pair of elements 24,36, that is against element 24. This, too, would result in the juxtaposition of two flat faces, simplifying bonding, but with the disadvantages mentioned above in relation to ribbed outer faces.
• Figure 4 illustrates an alternative embodiment of the invention comprising a light- diverter assembly generally indicated 37 composed of two separate reflectors 38, 39 pivotally connected together along a common parallel edge by a pivotable connection 40 and one of which, the reflector 38, is pivotally mounted at 41 to the roof 12 of the enclosure adjacent the upper edge of the opening 13.
• the reflector 38 may a multiple refractor array as described in relation to Figures 2 or 3 or alternatively a stacked elementary reflector array of the type described in the applicant's earlier British Patent 2 255 945, namely one in which the reflective surfaces are formed as parallel elementary surfaces extending traversely with respect to the general plane of the element itself.
• This may be achieved by stacking together an array of sheets of transparent material and then cutting through the array perpendicular to the faces of the elements to provide cut sheets with a plurality of parallel interfaces or, alternatively, by bringing together two elements having parallel grooves or other indentations which, in the composite element define a plurality of reflective facets which are offset from one another parallel to the general place of the array.
• the reflector array 38 is pivotally mounted at a proximal edge by a pivot 41 to the roof 12, and by a pivot 40 at its distal edge to a plane reflector 39.
• the pivotable connections 40, 41 allow the two reflectors 38, 39 to be extended to the deployed position illustrated in Figure 4 or two a folded or "parked" position (also illustrated in Figure 4A) in which both lie substantially parallel to one another and to the roof line 12 and out of the direct line of sight of the operator opening 13.
• the stacked elemental refractor reflector array 38 comprises two transparent sheets 40, 41 each having a plane face 42,43 and an opposite ribbed face having asymmetric parallel grooves separated by correspondingly shaped ribs which, when placed together with the ribs and grooves interpenetrating one another as shown in Figure 4 A, define a plurality of air gaps or pockets 44 between alternate faces of the ribs or grooves, the other alternate faces being in contact with one another.
• This structure defines a plurality of interfaces acting as perfect reflectors by total internal reflection which reflect light incident thereon without dispersion so that no chromatic aberration takes place.
• the deflector array 38 offers no diversion of light arriving generally perpendicular to the plane of the element 38 (that is parallel to the planes defined by the air pockets 44) so that the operator's view through the opening 13 in that direction is not impaired. By having two reflectors the image is upright.
• Figure 4 also shows the device in its parked position and the lines of sight from an operator O through the opening 13 in the machine cabin (represented by the line LI) which represents the lowest view through the opening 13, and the lines L2 and L3 which show, respectively, the lowest view through the opening 13 by observing the reflector device 38 and a typical ray.
• the deflector device of the invention when used in machinery such as cranes or excavators which may from time to time require the operator to have visibility outside the range afforded by the opening in the cabin in which the operator is located, this can be achieved by deploying the deflector device of the invention.
• Figure 5 illustrates the device of the invention in an alternative configuration in which the plane reflector 39 is pivotally connected at 41 to an upper edge of an opening 13 whilst the stacked elemental reflector refractor array 38 is pivotally connected to the plane reflector 39 at the pivot 40.
• This allows a more compact folding or parking configuration as illustrated in Figure 5 A and is particularly suitable for use at the rear of a vehicle such as a truck or van.
• Automatic deployment of the device can be arranged when reverse gear is engaged.
• the plane mirror 39 may be a flat plane mirror or may be concave or convex to vary the magnification of the image.
• the shapes of the facets in the two interpenetrating prism arrays may be curved or flat as shown.
• Figure 6 illustrates an alternative embodiment, similar to that of Figure 5, but in which a plane reflector is formed in the undersurface of a rear spoiler 45 projecting rearwardly from the roofline 12 over the opening 13.
• the stacked elemental reflector refractor array 38 is directly pivotally connected to the upper edge of the opening 13 at a pivot 46 so that it can turn between the deployed position illustrated in Figure 6 and the parked position illustrated in Figure 6A.
• FIG. 7 illustrates such an embodiment in which an upper portion 47 of the glazing in the opening 13 is formed as a stacked elemental reflector refractor array and a second such array 48 is pivotally connected at 49 to the roof 12 of the vehicle for movement between the deployed position (illustrated in solid outline) and the parked position (illustrated in broken outline).
• the pivoted array 48 is in the parked position the operator O can see straight through the fixed array 47 since light is only reflected at incident angles greater than a predetermined angle of incidence.
• Figures 8, 9 and 10 illustrate embodiments suitable for use at the front of a coach or heavy goods vehicle the windscreen 50 of which extends to a position such that a region represented by the letter A in front of the vehicle is obscured by the vehicle's nose. This is represented by the line of sight B from the eyes of the driver D to the ground.
• a light diverting device formed as an embodiment of the invention, and again comprising a stacked elemental reflector refractor array 38 pivotally connected to a mount 51, and a plane mirror 39 fixedly connected to the mount 51 allow the diversion of light from a region close to the front of the vehicle to reach the driver's eyes.
• Figure 9 illustrates a configuration in which a mirror 39 is pivotally connected to the windscreen 50 at a point above the mount 51 and the stacked elemental reflector refractor array 38 pivotally connected to it.
• This configuration has the advantage of allowing a view slightly closer to the front of the vehicle than that obtained by the embodiment of Figure 8, and can be stacked or parked in a slightly more compact configuration.

Applications Claiming Priority (3)

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• 1999
  • 1999-10-08 GB GBGB9923780.2A patent/GB9923780D0/en not_active Ceased
• 2000
  • 2000-10-09 WO PCT/GB2000/003845 patent/WO2001026930A1/en not_active Application Discontinuation
  • 2000-10-09 KR KR1020027004522A patent/KR20020057971A/ko not_active Application Discontinuation
  • 2000-10-09 JP JP2001529965A patent/JP2003511730A/ja active Pending
  • 2000-10-09 EP EP00966290A patent/EP1218222A1/de not_active Withdrawn
  • 2000-10-09 GB GB0024650A patent/GB2357067A/en not_active Withdrawn
  • 2000-10-09 AU AU76735/00A patent/AU7673500A/en not_active Abandoned

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