Prismatic rear viewing system for motor vehicles

Claim 2

A prismatic rear viewing system for a motor vehicle having an opening in the roof thereof, comprising: a generally triangular prism adapted to be laterally positioned in said opening above and below said roof, said prism including first, second and third angularly related transparent plates having interior surfaces defining an elongated cavity, said first plate facing the driver of the vehicle, said second and third plates being disposed at equal acute angles with respect to said first plate and converging at an obtuse angle rearwardly of said first plate, reflective surfaces on the exterior surfaces of said second and third plates, means at the ends of said plates closing said cavity, a transparent fluid filling said cavity, said fluid having a refractive index which with the refractive index of said plates and the angles therebetween will cause an image incident on said first plate to be refracted to one of said reflective surfaces for refraction and reflection back toward the exterior surface of said first plate at an angle greater than the critical angle for the plates whereby the image will be totally internally reflected therefrom to the other reflective surface for reflection therefrom to said first plate and transmission to said driver.

Claim 3

In a motor vehicle having an opening in the roof thereof adjacent a windshield, a prismatic rear viewing system for providing the driver with a viewing field over the roof, comprising: a triangular prism posiitoned laterally within the opening and extending above and below said roof, said prism having three angularly related glass plates with interior surfaces defining a triangular cavity, end means closing the ends of said cavity, a liquid filling said cavity, one of said plates facing the driver of the vehicle and extending generally vertically through the opening above and below said roof, said one of said plates having an exterior surface defining a common entrance and exit face, the other two plates being equally angularly disposed with respect to said one of said plates and converging at an obtuse angle of around 120* rearwardly of said one of said plates, a reflective surface on the exterior of said other two plates, the fluid in said cavity having a suitable refractive index which with the refractive index of said plates and the angles between the plates will cause images incident on said entrance face to be transmitted from the reflective surfaces at greater than the critical angle for glass whereby the images will be totally interiorally reflected therefrom for transmission to the other reflective surface for reflection and refraction to the driver, expansion means fluidly communicating with said cavity, said expansion means maintaining a substantially constant pressure on the liquid to prevent fluid separation during vehicle movement and compensate for differential volumetric expaNsion between the liquid and the glass plates.

Claim 4

In a motor vehicle having an opening in the roof thereof adjacent a windshield, a prismatic rear viewing system for providing the driver with a viewing field over the roof, comprising: a triangular prism posiitoned laterally within the opening and extending above and below said roof, said prism having three angularly related glass plates with interior surfaces defining a triangular cavity, end means closing the ends of said cavity, a liquid filling said cavity, one of said plates facing the driver of the vehicle and extending generally vertically through the opening above and below said roof, said one of said plates having an exterior surface defining a common entrance and exit face, the other two plates being equally angularly disposed with respect to said one of said plates and converging at an obtuse angle of around 120* rearwardly of said one of said plates, a reflective surface on the exterior of said other two plates, the fluid in said cavity having a suitable refractive index which with the refractive index of said plates and the angles between the plates will cause images incident on said entrance face to be transmitted from the reflective surfaces at greater than the critical angle for glass whereby the images will be totally interiorally reflected therefrom for transmission to the other reflective surface for reflection and refraction to the driver, expansion means fluidly communicating with said cavity, said expansion means maintaining a substantially constant pressure on the liquid to prevent fluid separation during vehicle movement and compensate for differential volumetric expaNsion between the liquid and the glass plates.

Claim 5

In a motor vehicle having an opening in the roof thereof adjacent a windshield, a prismatic rear viewing system for providing the driver with a viewing field over the roof, comprising: a shield carried on the roof and surrounding the opening, said shield having a rearward viewing opening therein, a triangular prism positioned laterally within the roof opening, said prism having an upper portion located above the roof within said shield and a lower portion located within the vehicle, said prism having first, second and third angularly related glass plates extending laterally with respect to the roof opening, said plates having surfaces defining a triangular cavity, end plates closing the ends of said cavity, a liquid filling said cavity having a refractive index substantially the same as glass, said first glass plate being completely transparent and extending generally vertically through the roof opening above and below said roof, said first glass plate facing the driver and having an exterior surface defining an image entrance face aligned with said viewing opening in the shield and an image exit face facing the driver, said second plate located above said roof and angularly disposed at an acute angle of around 30* with respect to said first glass plate, the third glass plate located below said roof and angularly disposed at an acute angle of around 30* with respect to said first glass plate and converging with said second glass plate at an obtuse angle of around 120* rearwardly of said first glass plate, a first reflective surface on the exterior surface of said second glass plate, a second reflective surface on the exterior of said third glass plate, the overall refractive index of the glass plates and the liquid, and the angles between the plates causing images incident on said entrance face to be reflected to the first reflective surface and reflected therefrom at greater than the critical angle for glass with respect to said first glass plate whereby the images will be totally internally reflected therefrom to the second reflective surface for reflection to the exit face and refraction therefrom to the driver, an expansion bellows including a flexible diaphragm carried by one of said end plates, said diaphragm fluidly communicating with said cavity, a compressed spring member acting on said diaphragm and effective to maintain a substantially constant pressure on the liquid to prevent fluid separation during vehicle movement and to compensate for differential volumetric expansion between the liquid and the glass plates.

Claim 6

In a motor vehicle having an opening in the roof thereof adjacent a windshield, a prismatic rear viewing system for providing the driver with a viewing field over the roof, comprising: a shield carried on the roof and surrounding the opening, said shield having a rearward viewing opening therein, a triangular prism positioned laterally within the roof opening, said prism having an upper portion located above the roof within said shield and a lower portion located within the vehicle, said prism having first, second and third angularly related glass plates extending laterally with respect to the roof opening, said plates having surfaces defining a triangular cavity, end plates closing the ends of said cavity, a liquid filling said cavity having a refractive index substantially the same as glass, said first glass plate being completely transparent and extending generally vertically through the roof opening above and below said roof, said first glass plate facing the driver and having an exterior surface defining an image entrance face aligned with said viewing opening in the shield and an image exit face facing the driver, said second plate located above said roof and angularly disposed at an acute angle of around 30* with respect to said first glass plate, the third glass plate located below said roof and angularly disposed at an acute angle of around 30* with respect to said first glass plate and converging with said second glass plate at an obtuse angle of around 120* rearwardly of said first glass plate, a first reflective surface on the exterior surface of said second glass plate, a second reflective surface on the exterior of said third glass plate, the overall refractive index of the glass plates and the liquid, and the angles between the plates causing images incident on said entrance face to be reflected to the first reflective surface and reflected therefrom at greater than the critical angle for glass with respect to said first glass plate whereby the images will be totally internally reflected therefrom to the second reflective surface for reflection to the exit face and refraction therefrom to the driver, an expansion bellows including a flexible diaphragm carried by one of said end plates, said diaphragm fluidly communicating with said cavity, a compressed spring member acting on said diaphragm and effective to maintain a substantially constant pressure on the liquid to prevent fluid separation during vehicle movement and to compensate for differential volumetric expansion between the liquid and the glass plates.

Claim 7

A periscopic viewing system for viewing rearwardly over the roof of a motor vehicle by a viewer located interior of the vehicle, the roof having a laterally extending opening therein, said system comprising: a prism formed of a transparent media positioned laterally of the vehicle and extending through the opening in the roof; a planar transparent first surface on the front of an upper portion of the prism, said first surface facing the viewer and receiving images from the rear of the vehicle and refracting the images thereat; a planar reflective second surface on the rear of said upper portion of the prism, said second surface being angularly disposed with respect to said first surface to receive the images refracted at said first surface and to reflect said images therefrom; a planar transparent third surface on the front of a middle portion of said prism, said third surfaces being angularly disposed with respect to the images reflected from said second surface at greater than the critical angle of the prism media so as to totally internally reflect said images therefrom; a planar reflective fourth surface at the rear of said prism, said fourth surface being angularly disposed with respect to said third surface to receive the totally internally reflected images and reflect said images therefrom; a planar transparent fifth surface on the front of the lower portiOn of the prism for receiving the reflected images from said fourth surface, said fifth surface being angularly disposed with respect to the fourth surface so as to refract said images thereat for transmission to the viewer.

Claim 8

A periscopic viewing system for viewing rearwardly over the roof of a motor vehicle by a viewer located interior of the vehicle, the roof having a laterally extending opening therein, said system comprising: a prism formed of a transparent media positioned laterally of the vehicle and extending through the opening in the roof; a planar transparent first surface on the front of an upper portion of the prism, said first surface facing the viewer and receiving images from the rear of the vehicle and refracting the images thereat; a planar reflective second surface on the rear of said upper portion of the prism, said second surface being angularly disposed with respect to said first surface to receive the images refracted at said first surface and to reflect said images therefrom; a planar transparent third surface on the front of a middle portion of said prism, said third surfaces being angularly disposed with respect to the images reflected from said second surface at greater than the critical angle of the prism media so as to totally internally reflect said images therefrom; a planar reflective fourth surface at the rear of said prism, said fourth surface being angularly disposed with respect to said third surface to receive the totally internally reflected images and reflect said images therefrom; a planar transparent fifth surface on the front of the lower portiOn of the prism for receiving the reflected images from said fourth surface, said fifth surface being angularly disposed with respect to the fourth surface so as to refract said images thereat for transmission to the viewer.