Multi-resolution bar code reader
First Claim
1. A method of increasing a range of a working angle of a wand type reader during reading of optically encoded information, wherein the working angle is defined as the angle between a major axis of the wand type reader and a line normal to a surface on which the optically encoded information appears, said method comprising the steps of:
- (a) arranging light emitting and detecting elements in the wand to(i) optically sense light reflected from a first effective sensing spot of a first diameter, and simultaneously(ii) optically sense light reflected from a second effective sensing spot of a second diameter which is different from the first diameter;
(b) passing the first and second effective sensing spots over the optically encoded information for simultaneously;
(i) sensing the optically encoded information as it passes through the first effective sensing spot and in response thereto producing a sensing signal, and(ii) sensing the optically encoded information as it passes through the second effective sensing spot and in response thereto producing another sensing signal,wherein the diameters of the first and second effective sensing spots increase in proportion to increases in the working angle; and
(c) deriving a single decoded representation of the optically encoded information from the two sensing signals , wherein for different working angles at least one of the effective sensing spots will be of appropriate size to produce a valid reading of the optically encoded information.
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Accused Products
Abstract
The method and apparatus of this invention facilitate operation of a bar code reader over a wider range of working angle and for a wider range of bar code densities. The invention includes improved optics and sensing elements. The optics and sensing elements and/or the associated circuitry are arranged to provide two channels of data derived form the scanned bar code. The two channels have differing resolutions. Analysis of the data from the two channels provides a single decoded result. As the working angle and density vary at least one of the resolutions will be appropriate for sensing all or most of the bar coded data. The data from the channel producing a valid result can be used, or if neither channel produces a valid result by itself, data from each channel can be analyzed and valid portions of the data from both channels combined to produce the single decoded result.
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Citations
43 Claims
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1. A method of increasing a range of a working angle of a wand type reader during reading of optically encoded information, wherein the working angle is defined as the angle between a major axis of the wand type reader and a line normal to a surface on which the optically encoded information appears, said method comprising the steps of:
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(a) arranging light emitting and detecting elements in the wand to (i) optically sense light reflected from a first effective sensing spot of a first diameter, and simultaneously (ii) optically sense light reflected from a second effective sensing spot of a second diameter which is different from the first diameter; (b) passing the first and second effective sensing spots over the optically encoded information for simultaneously; (i) sensing the optically encoded information as it passes through the first effective sensing spot and in response thereto producing a sensing signal, and (ii) sensing the optically encoded information as it passes through the second effective sensing spot and in response thereto producing another sensing signal, wherein the diameters of the first and second effective sensing spots increase in proportion to increases in the working angle; and (c) deriving a single decoded representation of the optically encoded information from the two sensing signals , wherein for different working angles at least one of the effective sensing spots will be of appropriate size to produce a valid reading of the optically encoded information. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A wand type reader for reading optically encoded information at a wide range of a working angle, wherein the working angle is defined as the angle between a major axis of the wand type reader and a line normal to a surface on which the optically encoded information appears, said wand type reader comprising:
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(a) light emitting and detecting elements arranged in the wand to (i) optically sense light reflected from a first effective sensing spot of a first diameter for sensing the optically encoded information as it passes through the first effective sensing spot and in response thereto producing a sensing signal, and simultaneously (ii) optically sense light reflected from a second effective sensing spot of a second diameter which is different from the first diameter for sensing the optically encoded information as it passes through the second effective sensing spot and in response thereto producing another sensing signal, wherein the diameters of the first and second effective sensing spots increase in proportion to increases in the working angle; and (b) means for deriving a single decoded representation of the optically encoded information from the two sensing signals, wherein for different working angles at least one of the effective sensing spots will be of appropriate size to produce a valid reading of the optically encoded information. - View Dependent Claims (8)
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9. A method of reading optically encoded information comprising the steps of:
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optically exposing encoded information; sensing light reflected from the optically encoded information to simultaneously produce two data streams related to the optically encoded information, wherein said two data streams have respectively two different resolutions; and deriving a single decoded representation of the optically encoded information from the two data streams of different resolutions. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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16. A system for reading optically encoded information comprising:
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sensor means for optically sensing the encoded information, and in response thereto, producing at least one electrical signal corresponding to the sensed optically encoded information; means responsive to said at least one electrical signal for simultaneously deriving two channels of data for each scan or pass of the encoded information by the sensor means, the two channels of data having respectively two different resolutions, one resolution being higher than the other resolution; and a decoder responsive to both channels of derived data for producing a single data output representative of the sensed optically encoded information. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A method of increasing a range of a working angle of a wand type reader during reading of optically encoded information, wherein the working angle is defined as the angle between a major axis of the wand type reader and a line normal to a surface on which the optically encoded information appears, said method comprising the steps of:
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(a) arranging light emitting and detecting elements in the wand to (i) optically sense light reflected from a first effective sensing spot of a first diameter, and (ii) optically sense light reflected from a second effective sensing spot of a second diameter which is larger than the first diameter; (b) passing the first and second effective sensing spots over the optically encoded information for (i) sensing the optically encoded information as it passes through the first effective sensing spot and in response thereto producing a first sensing signal, and (ii) sensing the optically encoded information as it passes through the second effective sensing spot and in response thereto producing a second sensing signal, wherein the diameters of the first and second effective sensing spots increase in proportion to increases in the working angle; and (c) deriving a single decoded representation of the optically encoded information from the two sensing signals, wherein the different working angles at least one of the effective sensing spots will be of appropriate size to produce a valid reading of the optically encoded information, the deriving step comprising; attempting to decode data from one of the sensing signals; if the attempt to decode data from the one sensing signal is successful, utilizing the data decoded from the one sensing signal as the decoded representation of the optically encoded information; if the attempt to decode the one sensing signal is unsuccessful, attempting to decode data from the other one of the sensing signals; if the attempt to decode data from the other one of the sensing signals is successful, utilizing the data decoded from the other one of the sensing signals as the decoded representation of the optically encoded information; and if the both of the attempts to decode data from the sensing signals were unsuccessful,;
analyzing said one of the sensing signals to recognize and decode any portions thereof which represent information within acceptable parameters, analyzing said other one of the sensing signals to recognize and decode any portions thereof which represent information within acceptable parameters, and combining the recognized and decoded portions of both sensing signals to produce the single decoded representation of the optically encoded information.
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41. A method of reading optically encoded information comprising the steps of:
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optically exposing encoded information; sensing light reflected from the optically encoded information to produce two data streams related to the optically encoded information, wherein said two data streams have respectively two different resolutions; and deriving a single decoded representation of the optically encoded information from the two data streams of different resolutions by; attempting to decode data from one of the data streams; if the attempt to decode data from the one data stream is successful, utilizing the data decoded from the one data stream as the decoded representation of the optically encoded information; if attempt to decode data from the one data stream was unsuccessful, attempting to decode data from the other one of the data streams; if the attempt to decode data from the other one of the data streams is successful, utilizing the data decoded from the other one of the data streams to produce the decoded representation of the optically encoded information; and if the data derived from both of the sensing signals indicates information not within acceptable parameters;
analyzing said one of the sensing signals to recognize and decode any portions thereof which represent information within acceptable parameters, analyzing said other one of the sensing signals to recognize and decode any portions thereof which represent information within acceptable parameters, and combining the recognized and decoded portions of both sensing signals to produce the single decoded representations of the optically encoded information.
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42. A method of reading optically encoded information, comprising the step of:
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optically exposing encoded information; sensing light reflected from the optically encoded information to produce, simultaneously, two data streams related to the optically encoded information, wherein said two data streams have respectively two different resolutions; and successively attempting to decode each data stream and decoding whichever data stream is first determined to contain data representing legitimate information, to thereby derive a single decoded representation of the optically encoded information from the two data streams.
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43. A system for reading optically encoded information, comprising:
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sensor means for optically sensing the encoded information, and in response, producing at least one electrical signal corresponding to the sensed optically encoded information; means responsive to said at least one electrical signal for simultaneously deriving two channels of data for each scan or pass of the encoded information by the sensor means, the two channels of data having respectively two different resolutions, one being greater than the other; and a decoder responsive to both channels of derived data for successively attempting to decode each channel and decoding whichever channel is first determined to contain data representing legitimate information to produce a single data output representative of the sensed optically encoded information.
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Specification