Sensor cover and method of construction thereof

Information

  • Patent Grant
  • 6750819
  • Patent Number
    6,750,819
  • Date Filed
    Thursday, January 10, 2002
    22 years ago
  • Date Issued
    Tuesday, June 15, 2004
    20 years ago
Abstract
A sensor cover is disclosed for camouflaging a high frequency sensor, including for example, a radar sensor. The sensor cover includes a substrate having a non-planar surface with non-signal transmitting regions and signal transmitting regions. A metal layer is disposed on each of the non-signal transmitting regions. Further, each of the non-signal transmitting regions is separated by one of the signal transmitting regions. The method of constructing such a sensor cover is also disclosed.
Description




TECHNICAL FIELD




The present invention relates generally to a radar sensor cover and, more specifically, to a sensor cover that allows minimal radar signal attenuation and minimal radiation pattern distortion.




BACKGROUND




The use of high frequency sensors in automotive detection and control systems is becoming more prevalent. One type of high frequency sensor frequently used in vehicular applications is a radar sensor. For example, adaptive cruise control (ACC) systems utilize a radar sensor to control the speed and distance of a vehicle equipped with an ACC system and a target vehicle. For aesthetic purposes, it is advantageous to hide the sensor components from view. However, the customary materials that are used for exterior vehicular shells, namely metals, are not transparent to the high frequency waves, including radar waves.




There are several prior art cover designs that are used to hide or camouflage the sensor components. One known cover design is made from an opaque non-metallic material that is essentially transparent to high frequency signals. A disadvantage of this type of cover is that the cover does not contain any metal and therefore does not blend in with the body of the vehicle.




Another known sensor cover design includes a very thin planar layer of metal. Such a structure is disclosed in U.S. Pat. No. 6,184,842 B1. The sensor cover in this disclosure includes a covering member formed of a radar-transparent material, an area formed on the surface of the radar-transparent material in the shape of a selected characteristic structure or symbol, a visible metallic or metallically glossy layer on the structure or symbol where the thickness of the metallic or metallically glossy layer is such that electromagnetic radiation of the radar system penetrates it substantially without attenuation. A disadvantage of this type of system is that the metallic area must be minimal to obtain minimal signal attenuation.




Thus, there is a need for metallic sensor covers that allow for a large metallic area and that provide minimal sensor signal attenuation. This invention provides such an improved/new and useful sensor cover.




BRIEF SUMMARY




The present invention overcomes the disadvantages described above of known sensor covers. An aspect of this invention is to form a high frequency electromagnetic wave transparent cover that can be designed as a decorative structure, such as a logo or manufacturer nameplate, or as any vehicle component, such as a grill. The cover is therefore aesthetically pleasing, while also providing the advantage of allowing transmission of high frequency electromagnetic waves, including radar waves, with minimal interference. This invention will disclose several constructions that have a metallic appearance from an elevational view, but allow high frequency wave transmission.




The present invention provides a sensor cover for camouflaging a high frequency electromagnetic wave transmitting sensor. The sensor cover includes a substrate having a non-planar surface wherein the surface has non-signal transmitting regions and signal transmitting regions. Each of the non-signal transmitting regions is separated by at least one of the signal transmitting regions. A metallic layer is disposed on each of the non-signal transmitting regions of the substrate.




The distance between the metal adhered non-signal transmitting regions and the repeat pattern of the metal adhered non-signal transmitting regions provide the visual appearance of a solid metal layer while allowing minimal attenuation and minimal radiation pattern or beam distortion of the sensor signal. The cover of the present invention may be used with a high frequency sensor is capable of both transmitting and receiving signals.




In another aspect of the present invention a method of constructing a sensor cover for camouflaging a high frequency sensor is provided. The method includes the steps of: A) forming a substrate having a non-planar surface, where the non-planar surface includes non-signal transmitting regions separated by signal transmitting regions; and B) adhering a metal layer on each of the non-signal transmitting regions of the substrate.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a vehicle including one embodiment of the present invention;





FIG. 2

is a top view of a vehicle including one embodiment of the present invention;





FIG. 3

is an elevational view of one embodiment of the present invention;




FIGS.


4


(A)-


4


(D) are side views of one embodiment of the present invention;




FIGS.


5


(A)-


5


(E) are side views of a first alternative embodiment of the present invention;




FIGS.


6


(A)-


6


(D) are side views of a second alternative embodiment of the present invention;




FIGS.


7


(A)-


7


(D) are side views of a third alternative embodiment of the present invention; and





FIG. 8

is a flowchart of a method of constructing the present invention.











DETAILED DESCRIPTION




The following description of the preferred embodiment of the invention is not intended to limit the invention to this preferred embodiment, but rather to enable any person skilled in the art of high frequency sensor coverings to make and use this invention.




The high frequency sensor covering is used to camouflage a high frequency sensor, for example, a radar sensor. The high frequency sensor is capable of transmitting and receiving sensor signals. As shown in

FIG. 1

, the radar sensor


20


and cover, shown generally at


22


, can be mounted to a vehicle


24


, although it is important to note that this invention is not limited to sensors and coverings used in association with vehicles. The radar sensor


20


and cover


20


are shown mounted in the front region of the vehicle


24


in

FIG. 1

, however, this invention includes sensors and covers that are mounted at any position on the vehicle.




The cover


22


masks the location of the sensor


20


yet allows the radar signals


26


to pass through with manageably low attenuation and minimal radiation pattern or beam distortion, as illustrated in FIG.


1


. More specifically, the sensor


20


is mounted to the vehicle


24


and the sensor cover


22


is mounted adjacent the sensor


20


so that the sensor signals


26


are directed through the covering


22


.

FIG. 2

illustrates how the system will appear from the exterior of the vehicle


24


.




As shown in

FIG. 3

, the covering


22


includes a substrate


28


that is made from a material that is essentially transparent to high frequency signals, including but not limited to, polycarbonate. The substrate


28


has a non-planar surface


30


with a plurality of non-signal transmitting regions


32


and a plurality of signal transmitting regions


34


. Each of the non-signal transmitting regions


32


of the substrate


28


is separated by at least one of the signal transmitting regions


34


. Further, each of the non-signal transmitting regions


32


is spaced apart by a predetermined distance for allowing the transmission of high frequency signals


26


communicated by the high frequency sensor


20


. Each of the plurality of non-signal transmitting regions


32


is covered with a metal layer or similar material layer providing a metallic appearance.




In one embodiment of the present invention, as shown in FIGS.


4


(A)-


4


(D), the substrate


28


includes a surface having recesses


36


and peaks


34


. Preferably, the recesses


36


and peaks


34


are molded into the substrate


28


. The recesses


36


and peaks


34


form the non-planar surface


30


of the substrate


28


. In one embodiment, the signal transmitting regions


34


of the substrate


28


correspond to the peaks


34


formed on the substrate


28


and the non-signal transmitting regions


32


of the substrate


28


correspond to the recesses


36


on the substrate


28


.




However, in another embodiment the signal transmitting regions


34


of the substrate


28


correspond to the recesses


36


formed on the substrate


28


and the non-signal transmitting regions


32


of the substrate


28


correspond to the peaks


34


on the substrate


28


.




A metal material


38


is applied to the non-signal transmitting regions


36


of the substrate


28


. Preferably the metal material


38


is aluminum. In the final product, in one embodiment, the metal material


38


will only be present on the substrate recesses


36


and there will be no metal material present on the substrate peaks


34


. In other words, there will be areas of the substrate


28


covered with metal material


32


and other areas of the substrate


28


that are not covered with metal material


34


. The areas where the metal is present and forms a pattern can be described as a metal or wire network. In very general terms, in one embodiment, the signal transmitting regions are aligned generally perpendicular to the direction of the sensor signals


26


transmitted or received by the high frequency sensor


20


.




In another embodiment of the present invention, an outer layer may be applied to the sensor cover. The outer layer


40


is formed from a material that is transparent to high frequency sensor signals. This outer layer


40


may be made from an environmentally stable film and may be applied directly to the substrate


28


. The outer layer


40


may be applied to either the side of the substrate opposite the recesses or to the recessed side. The outer layer


40


can be attached to the substrate


28


using any number of techniques, including but not limited to, a second surface printing technique, lacquer printing, bonded appliqué or decal, or decorative in-molding.




The process of designing the non-planar surface


30


of the substrate


28


involves considering several factors. One factor includes the position of the mounted sensor


20


with respect to the cover


22


. Another factor includes the desired design of the cover


22


from an elevational view. For instance, the desired design of the cover


22


may be a manufacturers logo, it may be camouflaged with the front grill of a vehicle


24


, or it may be flush with the vehicle's metal bumper. Therefore, a customized design of the non-planar substrate


28


is required for each specific set of criteria.




Preferably, the substrate


28


is a molded sheet having two sides


30


,


42


with the recesses


36


and peaks


24


on at least one side


30


. In yet another embodiment, shown in FIGS.


3


and


4


(A)-


4


(D), the substrate


28


is molded with a parallel line topography on one side


30


. A parallel line topography means that the recesses


36


preferably appear to be a series of parallel lines from an elevational view of the non-planar side


30


of the substrate


28


.




As shown in FIG.


4


(B), the metal material


38


is applied to the recessed surface


30


of the substrate


28


. The metal material


38


can be applied using numerous techniques, including but not limited to, sputter coating or evaporation coating. The surface of the metal-coated recessed side


44


of the substrate


28


is then ground so that metal material only remains in the recesses


32


. FIG.


4


(C) illustrates the appearance of the substrate


28


with the recessed areas of the substrate coated with metal


32


and the substrate peaks


34


free of any metal material. As shown in FIG.


4


(D), an outer layer


40


may be applied to the side


42


of the substrate opposite the recessed side


30


.




An alternative embodiment, shown in FIGS.


5


(A)-


5


(E), includes two substrate portions


46


,


48


that are adhered together. Each substrate portion


46


,


48


has a first side


50


,


52


and a second side


54


,


56


. The first portion of substrate


46


has recesses


58


and peaks


60


along its first side


50


. The second portion of substrate


48


has recesses


58


and peaks


60


along its second side


56


. Similar to the first embodiment, metal material


38


is applied to the recessed side of each portion of substrate


50


,


56


. Then, the metal-coated recessed sides


62


,


64


of each portion


46


,


48


are ground so that metal only remains in the recessed areas


66


,


68


of each portion


46


,


48


.




The second side


54


of the first portion of substrate


46


is adhered to the first side


52


of the second portion of substrate


48


. Preferably, the portions


46


,


48


of substrate are adhered in such a manner that the recesses on the first portion


66


of substrate are offset from or misaligned with the recesses on the second portion


68


of substrate. An outer layer


40


may also be applied to either the first


46


or second portion


48


of the substrate.




Another embodiment is shown in FIGS.


6


(A)-


6


(D). A single sheet of substrate


70


is molded with recesses


72


,


74


and peaks


76


,


78


on both sides


80


,


82


. However, the recesses


72


on the first side


80


of the sheet


70


are offset from or misaligned with the recesses


74


on the second side


82


of the sheet


70


. Shown at FIG.


6


(B), a metal material


38


is adhered to both sides


80


,


82


of the substrate


70


. Preferably, the metal material is aluminum. Shown in FIG.


6


(C), each metal-coated side


84


,


86


of the substrate


70


is ground so that metal material only remains in the recesses


90


on each side


80


,


82


. FIG.


6


(D) illustrates applying an outer layer


40


to one side of the substrate. The application of the outer layer


40


is optional.




In all of the embodiments described above, the recesses had generally square shaped valleys. In still another embodiment, illustrated in FIGS.


7


(A)-


7


(D), the recesses are generally triangular in shape. It should be noted that these generally triangular shaped recesses could be incorporated into all of the previously described embodiments in place of the generally rectangular shaped recesses.




In FIG.


7


(A), the substrate


94


is molded with generally triangular shaped recesses


92


along one side


96


. A metal material


38


is adhered to the recessed side


96


of the substrate


94


in FIG.


7


(B). The recessed side of the metal-coated substrate


98


is ground in a grinding operation, as shown in FIG.


7


(C), thus removing the substrate peaks


100


and revealing areas of the substrate


94


that are not metal-coated. FIG.


7


(D) illustrates the addition of an outer layer


40


to the substrate


94


. The outer layer


40


is shown adhered to the side of the substrate


101


opposite the recesses. However, the outer layer could also be applied to the recessed side of the substrate.





FIG. 8

illustrates a method of constructing a sensor cover for camouflaging a high frequency sensor, shown generally at


120


. A substrate is formed with a non-planar surface, having a plurality of non-signal transmitting regions and a plurality of signal transmitting regions, at


122


. Each of the non-signal transmitting regions is separated by at least one of the signal transmitting regions. Another step involves adhering a metal layer to each of the non-signal transmitting regions of the substrate, at


124


. Another step that might be included is adhering an outer layer to the substrate, at


126


. Yet another step involves applying the substrate to the housing containing the high frequency sensor, shown at


128


. Alternatively, the substrate can be applied directly to the vehicle.




In all of the embodiments, the metal layer may be adhered to the non-planar surface of the substrate using numerous techniques, including but not limited to, sputter coating or evaporation coating. Additionally, in all of the embodiments, the metal layer may be removed from the signal transmitting region by polishing or grinding the non-planar surface.




The sensor cover may be attached to a frame that attaches to a housing holding the sensor or the housing may attach directly to the vehicle. Alternatively, the sensor cover may attach directly to a housing holding the sensor or directly to the vehicle.




As any person skilled in the art of high frequency sensor covers will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the preferred embodiment of the invention without departing from the scope of this invention as defined in the following claims.



Claims
  • 1. A sensor cover for camouflaging a high frequency electromagnetic wave transmitting sensor, the sensor cover comprising:a substrate having a non-planar surface, wherein the non-planar surface has a plurality of non-signal transmitting regions and a plurality of signal transmitting regions; a metal layer disposed on each of the plurality of non-signal transmitting regions of the substrate; and wherein each of the plurality of non-signal transmitting signal regions is separated by at least one of the plurality of signal transmitting regions.
  • 2. The sensor cover of claim 2 wherein each of the plurality of non-signal transmitting regions is spaced apart by a predetermined distance for allowing the transmission of high frequency signals.
  • 3. The sensor cover according to claim 1 further comprising an outer layer attached to the substrate.
  • 4. The sensor cover according to claim 3 wherein the outer layer is attached to the substrate using a second surface printing technique.
  • 5. The sensor cover according to a claim 3 wherein the outer layer is an environmental stable film.
  • 6. The sensor cover according to claim 1 wherein the substrate is made from a material essentially transparent to radar signals.
  • 7. The sensor cover according to claim 6 wherein the substrate is molded polycarbonate.
  • 8. The sensor cover according to claim 1 wherein the metal layer is aluminum.
  • 9. The sensor cover according to claim 1 wherein the metal layer is adhered to the substrate by sputter coating.
  • 10. The sensor cover according to claim 1 wherein the substrate has a first side and a second side and wherein the recesses are positioned in a misaligned manner on the first and the second sides of the substrate.
  • 11. The sensor cover according to claim 1 wherein the high frequency sensor is a radar sensor.
  • 12. The sensor cover according to claim 11 wherein the radar sensor is capable of transmitting radar signals and receiving radar signals.
  • 13. The sensor cover according to claim 12 wherein the signal transmitting regions are aligned generally perpendicular to the direction of a sensor signal transmitted by the high frequency sensor.
  • 14. The sensor cover according to claim 12 wherein the signal transmitting regions are aligned generally perpendicular to the direction of a sensor signal received by the high frequency sensor.
  • 15. A method for constructing a sensor cover for camouflaging a high frequency sensor, the method comprising:forming a non-planar surface in a substrate, wherein the non-planar surface has a plurality of non-signal transmitting regions and a plurality of signal transmitting regions; and adhering a metal layer on each of the plurality of non-signal transmitting regions of the substrate; and wherein each of the plurality of non-signal transmitting regions is separated by at least one of the plurality of signal transmitting regions.
  • 16. The method according to claim 15 further comprising the step of adhering an outer layer to the substrate.
  • 17. The method according to claim 16 further comprising the step of attaching the substrate to a housing containing the high frequency sensor.
  • 18. A sensor cover for camouflaging a high frequency electromagnetic wave transmitting sensor, the sensor cover comprising:a substrate having a non-planar surface, wherein the non-planar surface has a plurality of non-signal transmitting regions and a plurality of signal transmitting regions, and wherein the substrate has a first substrate portion having a first side and a second side and the non-signal transmitting regions are recesses that are formed in the first side of the first substrate portion and a second substrate portion wherein the second substrate portion is adhered to the first substrate portion, the second substrate portion having a first side and a second side and recesses formed in the second side of the second substrate portion wherein metal is adhered to the recesses in the second substrate portion; and a metal layer disposed on each of the plurality of non-signal transmitting regions of the substrate, and wherein each of the plurality of non-signal transmitting regions is separated by at least one of the plurality of signal transmitting regions.
  • 19. A sensor cover for camouflaging a high frequency electromagnetic wave transmitting sensor, the sensor cover comprising:a substrate having a non-planar surface, wherein the non-planar surface has a plurality of non-signal transmitting regions and a plurality of signal transmitting regions, and wherein the substrate has a first substrate portion having a first side and a second side and the non-signal transmitting regions are recesses that are formed in the first side of the first substrate portion and a second substrate portion wherein the second substrate portion is adhered to the first substrate portion, the second substrate portion having a first side and a second side and recesses formed in the second side of the second substrate portion wherein metal is adhered to the recesses in the second substrate portion; and a metal layer disposed on each of the plurality of non-signal transmitting regions of the substrate, and wherein each of the plurality of non-signal transmitting regions is separated by at least one of the plurality of signal transmitting regions, and wherein the first substrate portion and the second substrate portion are adhered together such that the recesses on the first substrate portion and the recesses on the second substrate portion are misaligned.
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Entry
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