Method and apparatus for raster scanning of images
First Claim
1. An optical scanner for scanning an object having areas of different light reflectivity, the scanner comprising:
- an optical source constructed and positioned to produce an outgoing light beam that moves in a path along a two-dimensional raster scan pattern over the object, wherein the raster scan pattern includes a scanning direction and a direction generally orthogonal to the scanning direction;
an optical detector constructed and positioned to receive light reflected from the object and to produce a signal representative of reflectivity differences of the object along the path of the light beam; and
at least one beam position sensor in the path of the outgoing light beam, the sensor being constructed and positioned to provide an output indicative of the location of the beam along the generally orthogonal direction of the raster scan pattern.
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Accused Products
Abstract
A scanner has a window in its housing through which the scanning beam emerges to impinge upon an indicia to be read. The beam scans in a raster fashion over the window, and as it does so it impinges upon beam position indicating means which locate the position of the beam with respect to the scanner in at least certain portions of the scan pattern. Specifically, the beam position indicating means determines the position of the beam in a direction perpendicular to the overall scanning direction. In a preferred embodiment, the beam position indicating means may comprise one or more CCD'"'"'s which provide electrical output signals dependent upon the position of the beam when it impinges upon them. Alternatively, the beam position indicating means may comprise passive code means such as a stacked series of bar code symbols. The location of the beam when it scans across the symbol can be determined by the unique pattern of reflections.
75 Citations
33 Claims
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1. An optical scanner for scanning an object having areas of different light reflectivity, the scanner comprising:
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an optical source constructed and positioned to produce an outgoing light beam that moves in a path along a two-dimensional raster scan pattern over the object, wherein the raster scan pattern includes a scanning direction and a direction generally orthogonal to the scanning direction; an optical detector constructed and positioned to receive light reflected from the object and to produce a signal representative of reflectivity differences of the object along the path of the light beam; and at least one beam position sensor in the path of the outgoing light beam, the sensor being constructed and positioned to provide an output indicative of the location of the beam along the generally orthogonal direction of the raster scan pattern. - View Dependent Claims (2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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3. A method for optically scanning an object having areas of different light reflectivity, the method comprising the steps of:
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using an optical source to scan a light beam across the object in path along a two-dimensional raster scan pattern, wherein the raster scan pattern includes a scanning direction and a direction generally orthogonal to the scanning direction; using an optical detector to detect light reflected from the object and to produce a signal representative of reflectivity differences of the object along the path of the light beam; and positioning at least one beam detection sensor in the path of the outgoing light beam to provide an output indicative of the location of the beam along the generally orthogonal direction of the raster scan pattern. - View Dependent Claims (4)
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21. An optical scanner for optically scanning an object having areas of different light reflectivity, the scanner comprising:
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an optical source including means for scanning a light beam across the object in a path along a two-dimensional raster scan pattern, wherein the raster scan pattern includes a scanning direction and a direction generally orthogonal to the scanning direction; an optical detector including means for detecting light reflected from the object and producing a signal representative of reflectivity differences of the object along the path of the light beam; and at least one beam detection sensor in the path of the outgoing light beam, said sensor including means for providing an output indicative of the location of the beam along the generally orthogonal direction of the raster scan pattern.
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22. An optical scanner for scanning an object having areas of different light reflectivity, the scanner comprising:
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an optical source constructed and positioned to produce an outgoing light beam that moves in a two-dimensional raster scan pat tern over the object, wherein the raster scan pattern includes a scanning direction and a direction generally orthogonal to the scanning direction; an optical detector constructed and positioned to receive light reflected from the object and to produce a signal representative of reflectivity differences of the object along the path of the light beam; and a plurality of different bar code symbols in the path of the outgoing light beam, each positioned between the optical source and the object at a different location along at least the generally orthogonal direction of the raster scan pattern, the bar code symbol being configured to provide an output indicative of the location of the beam along the generally orthogonal direction of the raster scan pattern. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
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Specification