Illumination system

Claim 2

An illumination system for illuminating an object, comprising: an elliptical cylindrical mirror; an illumination source positioned on a first focal line of the mirror and focused to provide illumination of said object along the second focal line of the mirror; first and second mirror means positioned in first and second parallel planes, respectively, which are located adjacent to opposite boundaries of the object to be illuminated; and third and fourth mirror means, which are positioned to constitute end elements of the cylindrical surface defining said elliptical cylindrical mirror; whereby illumination from said illumination source is reflected from said cylindrical mirror and said first, second, third and fourth mirror means to increase the relative illumination adjacent to the boundaries of the object to be illuminated.

Claim 3

The illumination system of claim 1 in which the planes of said first and second mirror means are parallel to each other.

Claim 4

The illumination system of claim 1, in which each of said third and fourth mirror means is positioned in a plane.

Claim 5

The illumination system of claim 3 in which the planes of said third and fourth mirror means are parallel to each other.

Claim 6

The illumination system of claim 3 in which the planes of said first, second, third and fourth mirror means are parallel.

Claim 7

The illumination system of claim 1 in which the illumination source comprises a single element.

Claim 8

The illumination system of claim 1 in which the illumination source comprises a plurality of elements spaced along the first focal line.

Claim 9

The illumination system of claim 1 in which each of the third and fourth mirror means comprises a plurality of stepped parallel mirror surfaces.

Claim 10

An illumination system for illuminating a planar object, comprising: an elliptical cylindrical mirror; an illumination source positioned on a first focal line of the mirror and focused to provide illumination of said planar object at a position extending through the second focal line of the mirror; first and second mirror means positioned in first and second parallel planes, respectively, which are perpendicular to said position and which are located adjacent to opposite boundaries of the planar object to be illuminated; and third and fourth mirror means positioned in third and fourth planes, respectively, which are parallel to said second and third planes, said third and fourth mirror means being positioned to intersect the cylindrical surface defining said elliptical cylindrical mirror so that the third and fourth mirror means constitute end elements thereof; whereby illumination from said illumination source is reflected from said mirror and said first, second, third and fourth mirror means to increase the relative illumination adjacent to the boundaries of the object to be illuminated.

Claim 11

An illumination system for illuminating a planar object, comprising: an elliptical cylindrical mirror; an illumination source positioned on a first focal line of the mirror and focused to provide illumination of said planar object at a position extending through the second focal line of the mirror; first and second mirror means positioned in first and second parallel planes, respectively, which are perpendicular to said position and which are located adjacent to opposite boundaries of the planar object to be illuminated; and third and fourth mirror means positioned in third and fourth planes, respectively, which are parallel to said second and third planes, said third and fourth mirror means being positioned to intersect the cylindrical surface defining said elliptical cylindrical mirror so that the third and fourth mirror means constitute end elements thereof; whereby illumination from said illumination source is reflected from said mirror and said first, second, third and fourth mirror means to increase the relative illumination adjacent to the boundaries of the object to be illuminated.

Claim 12

A document sensing system comprising: a track along which a document may be moved for sensing information therefrom, said track including walls for restraining undesired movement of the document and also including a slit in one of said walls through which the document may be sensed; an elliptical mirror means positioned to direct illumination through said slit to enable reading of information from said document as it is moved past said slit; an illumination source positioned on a first focal line of the mirror means and focused by said elliptical mirror means to provide illumination of said document through said slit at a position substantially coincident with the second focal line of the mirror; second and third mirror means positioned in first and second planes, respectively, which are adjacent to boundaries of the document to be illuminated; fourth and fifth mirror means which constitute end elements of said elliptical mirror means; and illumination sensing means for receiving illumination generated by said illumination source and reflected from said object through said slit; whereby the second, third, fourth and fifth mirror means function to increase the relative illumination adjacent to the boundaries of said object.

Claim 13

A document sensing system comprising: a track along which a document may be moved for sensing information therefrom, said track including walls for restraining undesired movement of the document and also including a slit in one of said walls through which the document may be sensed; an elliptical mirror means positioned to direct illumination through said slit to enable reading of information from said document as it is moved past said slit; an illumination source positioned on a first focal line of the mirror means and focused by said elliptical mirror means to provide illumination of said document through said slit at a position substantially coincident with the second focal line of the mirror; second and third mirror means positioned in first and second planes, respectively, which are adjacent to boundaries of the document to be illuminated; fourth and fifth mirror means which constitute end elements of said elliptical mirror means; and illumination sensing means for receiving illumination generated by said illumination source and reflected from said object through said slit; whereby the second, third, fourth and fifth mirror means function to increase the relative illumination adjacent to the boundaries of said object.

Claim 14

The document sensing system of claim 10 in which the illumination sensing means includes a lens, and the increase of relative illumination adjacent to the boundaries of said object compensates for the vignetting effect of the lens.

Claim 15

The document sensing system of claim 11 in which the illumination sensing means also includes a linear array of sensing elements aligned in the same orientation as the slit in the track wall for receiving illumination reflected from said object and producing signals representative of information carried on said object.

Claim 16

The document sensing system of claim 10 in which said elliptical mirror means is disposed at an angle to the path of illumination from the slit in the track wall.

Claim 17

The document sensing system of claim 13 in which said angle is approximately thirty degrees.

Claim 18

The document sensing system of claim 10 in which said illumination source is a point source.

Claim 19

The document sensing system of claim 10 in which said illumination source comprises a plurality of point sources spaced along the first focal line of the elliptical mirror means.

Claim 20

The document sensing system of claim 10 in which said elliptical mirror means comprises a plurality of elliptical mirrors aligned along their focal lines and spaced apart from each other.

Claim 21

The document sensing system of claim 10 in which each of the fourth and fifth mirror means comprises a plurality of stepped parallel mirror surfaces.

Claim 22

The document sensing system of claim 10 in which each of the fourth and fifth mirror means is positioned in a plane.

Claim 23

The document sensing system of claim 9 in which the planes of said fourth and fifth mirror means are parallel to each other.

Claim 24

The document sensing system of claim 10 in which the planes of said second and third mirror means are parallel to each other.