Scanning apparatus

• US 4,149,091 A
• Filed: 05/02/1977
• Issued: 04/10/1979
• Est. Priority Date: 05/02/1977
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Crean, Peter A., Lavallee, Pierre A., Agulnek, Martin A.
• Primary Examiner(s): Dahl, Lawrence J.
• Application Number:
  US05/793,202
• Time in Patent Office: 708 Days
• Field of Search: 33/1 M, 250/566, 235/454, 235/456, 235/461
• US Class Current: 250/566
• CPC Class Codes: H04N 1/1017 the main-scanning components remaining positionally invariant with respect to one another in the sub-scanning direction
• CPC Class Codes: H04N 1/19505 Scanning picture elements spaced apart from one another in at least one direction
• CPC Class Codes: H04N 1/19515 in two directions

Abstract

A line scanning apparatus employing a multiplicity of linear arrays, the linear extent of which is less than the length of the scan line. To permit an entire line to be covered, the arrays are offset from one another in the direction of scan with adjoining array ends overlapped. To correct for the misalignment and redundancy introduced, the image data from the arrays is buffered until a line is completed when readout, is initiated. During readout, cross over from one array to the next is effected within the overlapped areas and the redundant data discarded.

Claims

1. In an apparatus for scanning an image line by line to produce data representative of the image scanned, the improvement comprising:

a movable carriage;

at least two arrays, each of said arrays comprising a plurality of discrete photosensitive elements arranged in succession along the linear axis of said array, the length of the viewing area of each array being less than the width of the image scanned;

means supporting said arrays on said carriage for scanning said image with the linear axis of said arrays extending in a direction substantially perpendicular to the direction of scanning movement of said carriage;

said arrays being supported so that said array viewing areas overlap whereby to provide a composite array viewing area having a length at least equal to the width of the image scanned;

means for actuating said carriage and said arrays to move said carriage and scan said image; and

readout means for reading out data from said arrays in succession, said readout means crossing over from one array to the next succeeding array within the overlapping portion of said array viewing areas.

2. The scanning apparatus according to claim 1 including data storage means for temporarily holding image data from said arrays pending completion of an image line.

3. The scanning apparatus according to claim 1 including control means to accommodate misalignment of said arrays in a direction perpendicular to the direction of scanning movement of said carriage.

4. The scanning apparatus according to claim 3 in which said control means includes adjustable counter means for each array, said counter means being individually settable to toll an interval reflecting the degree of misalignment of the array associated therewith relative to a predetermined reference point.

5. In an apparatus for scanning an image line by line to produce data representative of the image scanned, the combination of:

a platen for supporting an image to be scanned;

a carriage disposed in spaced operative relation with said platen;

means supporting said carriage for scanning movement relative to said platen;

drive means for moving said carriage;

at least two image reading arrays, said arrays being supported in side by side relationship on said carriage for scanning the image on said platen on scanning movement of said carriage;

means for actuatng said drive means to move said carriage and the arrays supported on said carriage past said platen whereby to scan the image on said platen upon activation of said arrays; and

array control means for activating said arrays to scan the image on said platen, said control means including delay means to selectively delay activation of said arrays individually until each array reaches a preset scanning point whereby to neutralize misalignment between said arrays in the direction of carriage scanning movement.

6. The apparatus according to claim 5 in which said arrays are supported such that a portion of the viewing areas thereof overlap, data from said array overlapping portions being redundant, and

means for removing said redundant data portions.

7. The apparatus according to claim 6 in which said last mentioned means includes

data storage means for temporarily storing data from each of said arrays including redundant data portions,

readout means for reading data in said storage means from said arrays in succession, said readout means crossing over from one array to the next successive array during said redundant data portions.

8. In an apparatus for scanning an image bearing original line by line to produce data representative of the image scanned, the improvement comprising:

at least two arrays, each of said arrays comprising a plurality of discrete photosensitive elements arranged in succession along the linear axis of said array,

means supporting said arrays in position to scan said original with the linear axis of said arrays extending in a direction substantially parallel to the scanned dimension of said original, the length of the viewing area of each array along said linear axis being less than the scanned dimension of the original;

said arrays being supported so that said array viewing areas overlap whereby to provide a composite array viewing area having a length at least equal to the scanned dimension of the original;

means providing relative movement between said arrays and said original; and

readout means for reading out data from said arrays, said readout means crossing over from one array to the next succeeding array within the overlapping portion of said array viewing areas.

9. In an apparatus for scanning image bearing originals to produce data representative of the image scanned, the improvement comprising:

a transparent platen for viewing said originals;

at least two arrays, each of said arrays comprising a plurality of discrete photosensitive elements arranged in succession along the linear axis of said array;

means supporting said arrays adjacent said platen for scanning said platen with the linear axis of said arrays extending in a direction substantially parallel to one dimension of said platen;

the length of the viewing area of each array along said linear axis being less than said platen one dimension;

said arrays being supported so that said array viewing areas overlap whereby to provide a composite array viewing area having a length at least equal to said platen one dimension; and

readout means for reading out data from said arrays, said readout means crossing over from one array to the next succeeding array within the overlapping portion of said array viewing areas.