Blackened optical transmission system

Claim 2

An optical transmission system, comprising: a transparent substrate having a front surface; a pair of elongated mutually parallel transparent ribs provided on the front surface, the ribs being laterally spaced to form a groove therebetween, and means for absorbing visible light, the means comprising an amount of light-absorbent discrete particles disposed in the groove, the amount being disposed such that the discrete particles disposed immediately adjacent to the transparent ribs are loose, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 3

A system as claimed in claim 1, further comprising means for containing the particles within the groove, the containing means including a layer comprising fused light-absorbent particles.

Claim 4

A system as claimed in claim 1, wherein each particle has a size in a range between approximately 0.5 and 20 microns diameter.

Claim 5

An optical transmission system, comprising: a substrate having a planar front surface; a plurality of elongate mutually parallel ribs provided on the front surface, the ribs being successively laterally adjacent, each rib being laterally spaced from a successively adjacent rib to form a respective groove therebetween, and means for absorbing visible light, the means comprising an amount of light-absorbent discrete particles disposed loosely in each groove, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 6

An optical transmission system, comprising: a substrate having a planar front surface; a plurality of elongate mutually parallel ribs provided on the front surface, the ribs being successively laterally adjacent, each rib being laterally spaced from a successively adjacent rib to form a respective groove therebetween, and means for absorbing visible light, the means comprising an amount of light-absorbent discrete particles disposed loosely in each groove, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 7

A system as claimed in claim 4, wherein each particle comprises a fusible material.

Claim 8

A system as claimed in claim 5, further comprising means for containing the particles within the grooves, the containing means including a black layer disposed in each groove, the layer comprising light-absorbent particles.

Claim 9

A system as claimed in claim 6, wherein each layer consists essentially of light-absorbent particles.

Claim 10

An optical transmission system, comprising: a substrate having a planar front surface and a rear surface opposite the front; a pair of elongated mutually parallel ribs provided on the front surface and interfaced with a surrounding medium, the ribs being laterally spaced to form a groove therebetween, the ribs being formed of a transparent medium having a first refractive index, the surrounding medium having a second refractive index, the first and the second refractive indexes determining a critical angle θ c for a total internal reflection of a light ray transmitted through the rear surface and incident upon the interface between a rib and the surrounding medium; and means, for absorbing visible light, the means including an amount of light-absorbent discrete particles disposed loosely within the groove, whereby the critical angle θ c is essentially unaffected by the particles.

Claim 11

An optical transmission system, comprising: a substrate having a planar front surface and a rear surface opposite the front; a pair of elongated mutually parallel ribs provided on the front surface and interfaced with a surrounding medium, the ribs being laterally spaced to form a groove therebetween, the ribs being formed of a transparent medium having a first refractive index, the surrounding medium having a second refractive index, the first and the second refractive indexes determining a critical angle θ c for a total internal reflection of a light ray transmitted through the rear surface and incident upon the interface between a rib and the surrounding medium; and means, for absorbing visible light, the means including an amount of light-absorbent discrete particles disposed loosely within the groove, whereby the critical angle θ c is essentially unaffected by the particles.

Claim 12

An optical transmission system, comprising: a transparent substrate having a front surface; a pair of elongated mutually parallel transparent ribs provided on the front surface, the ribs being laterally spaced to form a groove therebetween; and means, for absorbing visible light, the means comprising a light-absorbent skin extending between the ribs and over the groove, the skin being spaced from the front surface, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 13

An optical transmission system, comprising: a transparent substrate having a front surface; a pair of elongated mutually parallel transparent ribs provided on the front surface, the ribs being laterally spaced to form a groove therebetween; and means, for absorbing visible light, the means comprising a light-absorbent skin extending between the ribs and over the groove, the skin being spaced from the front surface, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 14

A system as claimed in claim 9, wherein the skin is formed by disposing an amount of black discrete fusible particles within the groove, and then fusing an outer portion of the disposed particles to form the skin.

Claim 15

A system as claimed in claim 10, wherein the particles have a number average particle size of approximately 10 microns diameter.

Claim 16

A system as claimed in claim 9, wherein the skin has an average thickness in a range of approximately 40 and 90 microns.

Claim 19

A method as claimed in claim 13, further comprising containing the particles within respective grooves.

Claim 20

A method as claimed in claim 14, wherein the containing step includes fusing a portion of the disposed particles to form a skin in each groove.

Claim 23

A method as claimed in claim 16, wherein the containing step includes fusing a portion of the particles disposed in each groove to form a skin extending between respective ribs.

Claim 24

An optical transmission system, comprising: a transparent substrate having a front surface; a pair of elongated mutually parallel transparent ribs provided on the front surface, the ribs being laterally spaced to form a groove therebetween, the groove containing an optical medium having a refractive index n≅1; and means for absorbing visible light, the means comprising a multiplicity of light-absorbent discrete particles disposed in the optical medium contained by the groove, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 25

An optical transmission system, comprising: a transparent substrate having a front surface; a pair of elongated mutually parallel transparent ribs provided on the front surface, the ribs being laterally spaced to form a groove therebetween, the groove containing an optical medium having a refractive index n≅1; and means for absorbing visible light, the means comprising a multiplicity of light-absorbent discrete particles disposed in the optical medium contained by the groove, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 26

A method of blackening an optical transmission system as claimed in claim 15, wherein fusing the portion of the disposed particles includes heating the portion.

Claim 27

A method of blackening an optical transmission system as claimed in claim 15, wherein fusing the portion of the disposed particles includes contacting the portion with a solvent.

Claim 28

A method as claimed in claim 20, wherein the solvent is trichloroethylene.

Claim 29

An optical transmission system as claimed in claim 1, 8 or 18, wherein the light-absorbent discrete particles disposed immediately adjacent to the ribs have shapes providing minimal optical contacts with the ribs.

Claim 30

An optical transmission system as claimed in claim 4, wherein, for each of the grooves, the light-absorbent discrete particles disposed immediately adjacent to the ribs have shapes providing optical contacts with the ribs.

Claim 31

A system as claimed in claim 22, wherein the ribs are contiguous along the front surface.

Claim 32

A system as claimed in claim 23, wherein each rib is contiguous with the successively adjacent rib.

Claim 33

A system as claimed in claim 24, wherein the shapes are round.

Claim 34

A system as claimed in claim 25, wherein the shapes are round.

Claim 35

A system as claimed in claim 1, 8 or 18, further comprising means for containing the particles within the groove, the containing means including a transparent film which is attached continuously along and is extended continuously between the ribs.

Claim 36

A system as claimed in claim 1, 8 or 18, further comprising means for containing the particles within the groove, the containing means consisting essentially of fused light-absorbent particles.

Claim 37

A system as claimed in claim 4, further comprising means for containing the particles within the grooves, the containing means including transparent films attached continuously along and extending continuously between respective ribs.

Claim 38

A system as claimed in claim 28, wherein the film includes a thermoplastic material.

Claim 39

A system as claimed in claim 30, wherein each film includes a thermoplastic material.

Claim 40

A system as claimed in claim 22, wherein each of the particles includes carbon black provided with a fusible polymer material.

Claim 41

A system as claimed in claim 23, wherein each of the particles includes carbon black provided with a fusible polymer material.

Claim 42

A system as claimed in claim 1, 8 or 18, wherein each light-absorbent discrete particle is a particle of an electrostatic photocopy machine toner powder.

Claim 43

A system as claimed in claim 4, wherein each light-absorbent discrete particle is a particle of an electrostatic photocopy machine toner powder.

Claim 44

A system as claimed in claim 22, wherein the light-absorbent discrete particles have respective chemical compositions which are not identical although light-absorbent.

Claim 45

A system as claimed in claim 23, wherein the amount includes particles having respective chemical compositions which are not identical although light-absorbent.

Claim 46

An optical transmission system, comprising: a transparent substrate having a planar front surface; a plurality of elongate transparent ribs provided on the front surface, the ribs being successively laterally adjacent, each rib being laterally spaced from a successively adjacent rib to form a respective groove therebetween; a multiplicity of light-absorbent discrete particles disposed loosely in each groove, the discrete particles having shapes such that the discrete particles disposed immediately adjacent to the ribs provide minimal optical contacts with the ribs; and a light-absorbent skin disposed in each groove, the skin extending between the ribs and over the multiplicity of discrete particles, the skin having a chemical composition consisting essentially of that of the discrete particles disposed loosely in the groove, whereby reflection of visible ambient light impinging on the system is reduced.

Claim 47

An optical transmission system, comprising: a transparent substrate having a planar front surface; a plurality of elongate transparent ribs provided on the front surface, the ribs being successively laterally adjacent, each rib being laterally spaced from a successively adjacent rib to form a respective groove therebetween; a multiplicity of light-absorbent discrete particles disposed loosely in each groove, the discrete particles having shapes such that the discrete particles disposed immediately adjacent to the ribs provide minimal optical contacts with the ribs; and a light-absorbent skin disposed in each groove, the skin extending between the ribs and over the multiplicity of discrete particles, the skin having a chemical composition consisting essentially of that of the discrete particles disposed loosely in the groove, whereby reflection of visible ambient light impinging on the system is reduced.