Apparatus for continuously controlled emission of light from prism light guide

Claim 2

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (iii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and, (d) said light guide contains a mechanism which causes light to escape from said light guide at a rate which varies along the length of said light guide, such that the mount of light escaping, per unit length, along said light guide has a selected distribution of values, wherein: (I) said mechanism is a substantially non light absorptive material; and, (II) the density of said material varies as a function of the length of said light guide.

Claim 3

A light guide, as defined in claim 1, wherein said central path is non linear.

Claim 4

A light guide as defined in claim 2, wherein said non linearity is such that light escapes from said light guide at a rate which varies as a function of the length of said light guide.

Claim 5

A light guide as defined in claim 3, wherein the amount of light escaping, per unit length, from said light guide is substantially constant along the length of said light guide.

Claim 6

A light guide as defined in claim 2, 3 or 4, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 7

A light guide, as defined in claim 1, wherein the average cross-sectional dimension of each of said plane segments is non constant.

Claim 8

A light guide as defined in claim 6, wherein said the average cross-sectional dimension of each of said plane segments varies such that light escapes from said light guide at a rate which varies as a function of the length of said light guide.

Claim 9

A light guide as defined in claim 7, wherein the amount of light escaping, per unit length, from said light guide is substantially constant along the length of said light guide.

Claim 10

A light guide as defined in claim 6, 7 or 8, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 11

A light guide as defined in claim 1, wherein: (a) a first portion of said light guide comprises prism light guide material; and, (e) the remaining portion of said light guide allows a substantial portion of light incident thereupon to escape therethrough.

Claim 12

A light guide as defined in claim 10, wherein the ratio of said first and remaining portions varies, along said light guide, such that a substantially constant amount of light escapes through said remaining portion at all points along said light guide.

Claim 13

A light guide as defined in claim 10 or 11, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said remaining portion is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 14

A light guide as defined in claim 11, wherein said remaining portion is formed by removing a selected amount of prism light guide material from a selected portion of said light guide.

Claim 15

A light guide as defined in claim 11, wherein said remaining portion is formed by altering the optical characteristics of a selected part of the prism light guide material initially forming part of said first portion to prevent specular total internal reflection of light within said light guide from occurring at said selected part.

Claim 16

A light guide as defined in claim 11, wherein said remaining portion is formed by placing in optical contact with a selected part of the prism light guide material initially forming part of said first portion, a substance which prevents specular total internal reflection of light within said light guide from occurring.

Claim 17

A light guide, having: (i) a central path comprising as the locus of points which are the centroids of the segments contained with in said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and (d) said light guide contains a mechanism which causes light to escape from said light guide at a rate which varies along the length of said light guide, such that the amount of light escaping, per unit length, along said light guide has a selected distribution of values, and further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 18

A light guide, having: (i) a central path comprising as the locus of points which are the centroids of the segments contained with in said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and (d) said light guide contains a mechanism which causes light to escape from said light guide at a rate which varies along the length of said light guide, such that the amount of light escaping, per unit length, along said light guide has a selected distribution of values, and further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 19

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and, (d) said central path is non linear.

Claim 20

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and, (d) said central path is non linear.

Claim 21

A light guide as defined in claim 17, wherein said non linearity is such that light escapes from said light guide at a rate which varies as a function of the length of said light guide.

Claim 22

A light guide as defined in claim 18, wherein the amount of light escaping, per unit length, from said light guide is substantially constant along the length of said light guide.

Claim 23

A light guide as defined in claim 17, 18 or 19, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 24

A light guide, as defined in claim 17, wherein the average cross-sectional dimension of each of said plane segments is non constant.

Claim 25

A light guide as defined in claim 21, wherein said the average cross-sectional dimension of each of said plane segments varies such that light escapes from said light guide at a rate which varies as a function of the length of said light guide.

Claim 26

A light guide as defined in claim 22, wherein the amount of light escaping, per unit length, from said light guide is substantially constant along the length of said light guide.

Claim 27

A light guide as defined in claim 21, 22 or 23, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 28

A light guide as defined in claim 17, (a) wherein a first portion of said light guide comprises prism light guide material; and, (e) the remaining portion of said light guide allows a substantial portion of light incident thereupon to escape therethrough.

Claim 29

A light guide as defined in claim 25, wherein the ratio of said first and remaining portions varies, along said light guide, such that a substantially constant amount of light escapes through said remaining portion at all points along said light guide.

Claim 30

A light guide as defined in claim 25 or 26, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said remaining portion is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 31

A light guide as defined in claim 26, wherein said remaining portion is formed by removing a selected amount of prism light guide material from a selected portion of said light guide.

Claim 32

A light guide as defined in claim 26, wherein said remaining portion is formed by altering the optical characteristics of a selected part of the prism light guide material initially forming part of said first portion to prevent specular total internal reflection of light within said light guide from occurring at said selected part.

Claim 33

A light guide as defined in claim 26, wherein said remaining portion is formed by placing in optical contact with a selected part of the prism light guide material initially forming part of said first portion, a substance which prevents specular total internal reflection of light within said light guide from occurring.

Claim 34

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and, (d) the average cross-sectional dimension of each of said plane segments is non constant.

Claim 35

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; and, (d) the average cross-sectional dimension of each of said plane segments is non constant.

Claim 36

A light guide as defined in claim 31, wherein said the average cross-sectional dimension of each of said plane segments varies such that light escapes from said light guide at a rate which varies as a function of the length of said light guide.

Claim 37

A light guide as defined in claim 32, wherein the amount of light escaping, per unit length, from said light guide is substantially constant along the length of said light guide.

Claim 38

A light guide as defined in claim 31, 32 or 33, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said light guide is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 39

A light guide as defined in claim 31, wherein: (a) a first portion of said light guide comprises prism light guide material; and, (e) the remaining portion of said light guide allows a substantial portion of light incident thereupon to escape therethrough.

Claim 40

A light guide as defined in claim 35, wherein the ratio of said first and remaining portions varies, along said light guide, such that a substantially constant amount of light escapes through said remaining portion at all points along said light guide.

Claim 41

A light guide as defined in claim 35 or 36, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said remaining portion is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 42

A light guide as defined in claim 36, wherein said remaining portion is formed by removing a selected amount of prism light guide material from a selected portion of said light guide.

Claim 43

A light guide as defined in claim 36, wherein said remaining portion is formed by altering the optical characteristics of a selected part of the prism light guide material initially forming part of said first portion to prevent specular total internal reflection of light within said light guide from occurring at said selected part.

Claim 44

A light guide as defined in claim 36, wherein said remaining portion is formed by placing in optical contact with a selected part of the prism light guide material initially forming part of said first portion, a substance which prevents specular total internal reflection of light within said light guide from occurring.

Claim 45

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (d) a first portion of said light guide comprises prism light guide material; and, (e) the remaining portion of said light guide allows a substantial portion of light incident thereupon to escape therethrough.

Claim 46

A light guide, having: (i) a central path comprising the locus of points which are the centroids of the segments contained within said light guide of all planes which intersect said light guide and which are oriented such that the area of each of said plane segments is a minimum; and, (ii) an average cross-sectional dimension comprising, for each one of said plane segments, the average length of those portions of all lines within said light guide which lie on said one plane segment and which intersect said light guide; wherein: (a) the length of said light guide is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (b) the fractional rate of change, along said light guide, of substantially all randomly selected cross-sectional dimensions of said light guide, is substantially less than the reciprocal of the average cross-sectional dimension of substantially all of said plane segments; (c) the radius of curvature of said central path at substantially all randomly selected points on said central path is substantially greater than the average cross-sectional dimension of substantially all of said plane segments; (d) a first portion of said light guide comprises prism light guide material; and, (e) the remaining portion of said light guide allows a substantial portion of light incident thereupon to escape therethrough.

Claim 47

A light guide as defined in claim 41, wherein the ratio of said first and remaining portions varies, along said light guide, such that a substantially constant amount of light escapes through said remaining portion at all points along said light guide.

Claim 48

A light guide as defined in claim 41 or 42, further comprising an external cover over at least a portion of said light guide, whereby: (a) a portion of the light which escapes from said remaining portion is transmitted through said cover and away from said light guide; and, (b) the remaining portion of said escaping light is reflected by said cover back into said light guide.

Claim 49

A light guide as defined in claim 42, wherein said remaining portion is formed by removing a selected amount of prism light guide material from a selected portion of said light guide.

Claim 50

A light guide as defined in claim 42, wherein said remaining portion is formed by altering the optical characteristics of a selected part of the prism light guide material in initially forming part of said first portion to prevent specular total internal reflection of light within said light guide from occurring at said selected part.

Claim 51

A light guide as defined in claim 42, wherein said remaining portion is formed by placing in optical contact with a selected part of the prism light guide material initially forming part of said first portion, a substance which prevents specular total internal reflection of light within said light guide from occurring.