US5612531A
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Bar code reader with multiple sensitivity modes using variable thresholding comparisons
Assignee: Symbol Technologies LLC
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Filing: 1995-06-07
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Granted: 1997-03-18
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Expires: 2015-06-07
Abstract
Abstract A multiple sensitivity-mode digitizer circuit for a bar code reader has circuits that perform two thresholding techniques. The bar code reader includes a first derivative circuit for receiving an analog signal from a scan of the bar code symbol and for generating a first derivative signal of the analog signal. The digitizer circuit includes a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity. A second thresholding circuit generates a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity. A mode selector selects as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Inventors
- 👤 Edward Barkan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:03
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10861; G06K7/10871; G06K7/10554; G06K7/10564; G06K7/10584; G06K7/10594; G06K7/10603; G06K7/10633; G06K7/10643; G06K7/10653; G06K7/10673; G06K7/10683; G06K7/10693; G06K7/10792; G06K7/10801; G06K7/10811; G06K7/10851; G06K7/10881; G06K7/10891; G06K7/109; G06K7/14; G06K7/1404; G06K7/146; G06K7/1478; G06K2207/00; G06K2207/1011; G06K2207/1016; G06K2207/1018
Claims Analysis
Total Claims: 79
Claim 1
Independent Claim
159 words
A multiple sensitivity-mode digitizer circuit for a bar code reader for generating an output digitized signal corresponding to data encoded in a scanned bar code symbol, the bar code reader having a first derivative circuit for receiving an analog signal from a scan of the bar code symbol and for generating a first derivative signal of the analog signal, and the digitizer circuit comprising: a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and a mode selector for selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 2
Dependent Claim
159 words
A multiple sensitivity-mode digitizer circuit for a bar code reader for generating an output digitized signal corresponding to data encoded in a scanned bar code symbol, the bar code reader having a first derivative circuit for receiving an analog signal from a scan of the bar code symbol and for generating a first derivative signal of the analog signal, and the digitizer circuit comprising: a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and a mode selector for selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 3
Dependent Claim
53 words
The digitizer circuit according to claim 1, wherein the digitizer circuit has a first sensitivity mode and a second sensitivity mode, the mode selector selecting the first digitized signal when the circuit is in the first sensitivity mode and selecting the third digitized signal when the circuit is in the second sensitivity mode.
Claim 4
Dependent Claim
23 words
The digitizer circuit according to claim 2, wherein the mode selector includes a microprocessor for selecting the operating mode of the digitizer circuit.
Claim 5
Dependent Claim
38 words
The digitizer circuit according to claim 3, wherein the microprocessor includes means for selecting the operating mode of the digitizer circuit synchronously with a beginning of a scan of the bar code symbol by the bar code reader.
Claim 6
Dependent Claim
38 words
The digitizer circuit according to claim 3, wherein the microprocessor includes means for selecting the operating mode of the digitizer circuit synchronously with an end of a scan of the bar code symbol by the bar code reader.
Claim 7
Dependent Claim
24 words
The digitizer circuit according to claim 2, wherein the mode selector includes a logic circuit for selecting the operating mode of the digitizer circuit.
Claim 8
Dependent Claim
31 words
The digitizer circuit according to claim 6, wherein the logic circuit includes means for selecting the operating mode of the digitizer circuit synchronously with a beginning of a bar code scan.
Claim 9
Dependent Claim
31 words
The digitizer circuit according to claim 6, wherein the logic circuit includes means for selecting the operating mode of the digitizer circuit synchronously after an end of a bar code scan.
Claim 10
Dependent Claim
23 words
The digitizer circuit according to claim 2, wherein the mode selector includes means for manually programming the operating mode of the digitizer circuit.
Claim 11
Dependent Claim
31 words
The digitizer circuit according to claim 2, wherein the mode selector includes a decoder for analyzing the first and second digitized signal and selecting the operating mode of the digitizer circuit.
Claim 12
Dependent Claim
37 words
The digitizer circuit according to claim 2, wherein the mode selector includes means for determining a symbol quality of the scanned bar code symbol; and means for selecting an appropriate threshold sensitivity value and the operating mode.
Claim 13
Dependent Claim
55 words
The digitizer circuit according to claim 2, wherein the mode selector selects the first sensitivity mode for a bar code with bars and spaces of a first width and selects the second sensitivity mode for a bar code with bars and spaces of a second width, the second width being greater than the first width.
Claim 14
Dependent Claim
27 words
The digitizer circuit according to claim 2, wherein the third digitized signal corresponds to peaks of the first derivative signal that exceed the first and second thresholds.
Claim 15
Dependent Claim
53 words
The digitizer circuit according to claim 1, wherein the mode selector includes means for varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and means for selecting an optimum threshold sensitivity value in response to the means for varying the threshold sensitivity value.
Claim 16
Dependent Claim
23 words
The digitizer circuit according to claim 1, further comprising a margin threshold circuit to control outputting of the first and third digitized signals.
Claim 17
Dependent Claim
50 words
The digitizer circuit according to claim 1, wherein the first threshold includes a first and second value and wherein the first threshold circuit compares positive peaks of the first derivative signal to the first threshold value and compares negative peaks of the first derivative signal to the second threshold value.
Claim 18
Dependent Claim
50 words
The digitizer circuit according to claim 16, wherein the second threshold includes a third and fourth value and wherein the second threshold circuit compares positive peaks of the first derivative signal to the third threshold value and compares negative peaks of the first derivative signal to a fourth threshold value.
Claim 19
Dependent Claim
19 words
The digitizer circuit according to claim 17, wherein the third threshold value is a predetermined value above analog ground.
Claim 20
Dependent Claim
19 words
The digitizer circuit according to claim 17, wherein the fourth threshold value is a predetermined value below analog ground.
Claim 21
Dependent Claim
20 words
The digitizer circuit according to claim 17, wherein the first threshold value is less sensitive than the third threshold value.
Claim 22
Dependent Claim
20 words
The digitizer circuit according to claim 17, wherein the second threshold value is less sensitive than the fourth threshold value.
Claim 23
Dependent Claim
33 words
The digitizer circuit according to claim 16, wherein the first threshold value being compared to a positive peak is a predetermined value below a preceding positive peak value of the first derivative signal.
Claim 24
Dependent Claim
33 words
The digitizer circuit according to claim 16, wherein the second threshold value being compared to a negative peak is a predetermined value above a preceding negative peak value of the first derivative signal.
Claim 25
Dependent Claim
148 words
A multiple sensitivity-mode bar code reader for decoding data encoded in a scanned bar code symbol, comprising: a first derivative circuit for receiving an analog signal from a scan of the bar code symbol and for generating a first derivative signal of the analog signal; a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; a mode selector for selecting an output digitized signal from one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal; and a decoder for decoding the output digitized signal.
Claim 26
Dependent Claim
148 words
A multiple sensitivity-mode bar code reader for decoding data encoded in a scanned bar code symbol, comprising: a first derivative circuit for receiving an analog signal from a scan of the bar code symbol and for generating a first derivative signal of the analog signal; a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; a mode selector for selecting an output digitized signal from one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal; and a decoder for decoding the output digitized signal.
Claim 27
Dependent Claim
55 words
The bar code reader according to claim 24, wherein the bar code reader has a first sensitivity mode and a second sensitivity mode, the mode selector selecting the first digitized signal when the circuit is in the first sensitivity mode and selecting the third digitized signal when the circuit is in the second sensitivity mode.
Claim 28
Dependent Claim
24 words
The bar code reader according to claim 25, wherein the mode selector includes a microprocessor for selecting the operating mode of the digitizer circuit.
Claim 29
Dependent Claim
39 words
The bar code reader according to claim 26, wherein the microprocessor includes means for selecting the operating mode of the digitizer circuit synchronously with a beginning of a scan of the bar code symbol by the bar code reader.
Claim 30
Dependent Claim
39 words
The bar code reader according to claim 26, wherein the microprocessor includes means for selecting the operating mode of the digitizer circuit synchronously with an end of a scan of the bar code symbol by the bar code reader.
Claim 31
Dependent Claim
25 words
The bar code reader according to claim 25, wherein the mode selector includes a logic circuit for selecting the operating mode of the digitizer circuit.
Claim 32
Dependent Claim
24 words
The bar code reader according to claim 25, wherein the mode selector includes means for manually programming the operating mode of the digitizer circuit.
Claim 33
Dependent Claim
38 words
The bar code reader according to claim 25, wherein the mode selector includes means for determining a symbol quality of the scanned bar code symbol; and means for selecting an appropriate threshold sensitivity value and the operating mode.
Claim 34
Dependent Claim
66 words
The bar code reader according to claim 25, wherein the mode selector selects the first sensitivity mode for wherein the mode selector selects the first sensitivity mode for a bar code with bars and spaces of a first width and selects the second sensitivity mode for a bar code with bars and spaces of a second width, the second width being greater than the first width.
Claim 35
Dependent Claim
54 words
The bar code reader according to claim 24, wherein the mode selector includes means for varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and means for selecting an optimum threshold sensitivity value in response to the means for varying the threshold sensitivity value.
Claim 36
Dependent Claim
24 words
The bar code reader according to claim 24, further comprising a margin threshold circuit to control outputting of the first and third digitized signals.
Claim 37
Dependent Claim
51 words
The bar code reader according to claim 24, wherein the first threshold includes a first and second value and wherein the first threshold circuit compares positive peaks of the first derivative signal to the first threshold value and compares negative peaks of the first derivative signal to the second threshold value.
Claim 38
Dependent Claim
51 words
The bar code reader according to claim 35, wherein the second threshold includes a third and fourth value and wherein the second threshold circuit compares positive peaks of the first derivative signal to the third threshold value and compares negative peaks of the first derivative signal to a fourth threshold value.
Claim 39
Dependent Claim
178 words
A multiple sensitivity-mode bar code reader for scanning bar code symbols comprising: an optical system including a laser beam generator for scanning a bar code symbol; sensing means, responsive to the optical system, for generating an analog signal corresponding to the bar code symbol; a first derivative circuit for generating a first derivative signal of the analog signal; a first digitizer circuit, coupled to the sensing means, for receiving the first derivative signal and generating an output digitized signal, the digitizer circuit including a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and a mode selector for selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 40
Dependent Claim
178 words
A multiple sensitivity-mode bar code reader for scanning bar code symbols comprising: an optical system including a laser beam generator for scanning a bar code symbol; sensing means, responsive to the optical system, for generating an analog signal corresponding to the bar code symbol; a first derivative circuit for generating a first derivative signal of the analog signal; a first digitizer circuit, coupled to the sensing means, for receiving the first derivative signal and generating an output digitized signal, the digitizer circuit including a first thresholding circuit for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; a second thresholding circuit for generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and a mode selector for selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 41
Dependent Claim
37 words
The bar code reader according to claim 37, wherein the optical system includes a laser focusing optics generating a laser beam cross section that is longer in a first height direction than in a second width direction.
Claim 42
Dependent Claim
54 words
The bar code reader according to claim 37, wherein the digitizer circuit has a first sensitivity mode and a second sensitivity mode, the mode selector selecting the first digitized signal when the circuit is in the first sensitivity mode and selecting the third digitized signal when the circuit is in the second sensitivity mode.
Claim 43
Dependent Claim
24 words
The bar code reader according to claim 39, wherein the mode selector includes a microprocessor for selecting the operating mode of the digitizer circuit.
Claim 44
Dependent Claim
38 words
The bar code reader according to claim 39, wherein the mode selector includes means for determining a symbol quality of the scanned bar code symbol; and means for selecting an appropriate threshold sensitivity value and the operating mode.
Claim 45
Dependent Claim
66 words
The bar code reader according to claim 39, wherein the mode selector selects the first sensitivity mode for wherein the mode selector selects the first sensitivity mode for a bar code with bars and spaces of a first width and selects the second sensitivity mode for a bar code with bars and spaces of a second width, the second width being greater than the first width.
Claim 46
Dependent Claim
54 words
The bar code reader according to claim 37, wherein the mode selector includes means for varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and means for selecting an optimum threshold sensitivity value in response to the means for varying the threshold sensitivity value.
Claim 47
Dependent Claim
51 words
The bar code reader according to claim 37, wherein the first threshold includes a first and second value and wherein the first threshold circuit compares positive peaks of the first derivative signal to the first threshold value and compares negative peaks of the first derivative signal to the second threshold value.
Claim 48
Dependent Claim
51 words
The bar code reader according to claim 44, wherein the second threshold includes a third and fourth value and wherein the second threshold circuit compares positive peaks of the first derivative signal to the third threshold value and compares negative peaks of the first derivative signal to a fourth threshold value.
Claim 49
Independent Claim
123 words
A method for outputting an output digitized signal corresponding to data encoded in a scanned bar code symbol, the method comprising the steps of: generating a first derivative signal of the analog signal, the first derivative signal having positive and negative peaks; generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 50
Independent Claim
123 words
A method for outputting an output digitized signal corresponding to data encoded in a scanned bar code symbol, the method comprising the steps of: generating a first derivative signal of the analog signal, the first derivative signal having positive and negative peaks; generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 51
Dependent Claim
68 words
The method for outputting an output digitized signal according to claim 46, wherein the first digitized signal is selected for wherein the mode selector selects the first sensitivity mode for a bar code with bars and spaces of a first width and selects the second sensitivity mode for a bar code with bars and spaces of a second width, the second width being greater than the first width.
Claim 52
Dependent Claim
53 words
The method for outputting an output digitized signal according to claim 46, wherein the first threshold includes a first and second value and wherein positive peaks of the first derivative signal are compared to the first threshold value and negative peaks of the first derivative signal are compared to the second threshold value.
Claim 53
Dependent Claim
53 words
The method for outputting an output digitized signal according to claim 48, wherein the second threshold includes a third and fourth value and wherein positive peaks of the first derivative signal are compared to the third threshold value and negative peaks of the first derivative signal are compared to the fourth threshold value.
Claim 54
Dependent Claim
43 words
The method for outputting an output digitized signal according to claim 49, wherein the step of selecting includes determining a symbol quality of the scanned bar code symbol; and selecting appropriate threshold sensitivity values for the first, second, third and fourth sensitivity values.
Claim 55
Dependent Claim
55 words
The method for outputting an output digitized signal according to claim 49, wherein the step of selecting includes varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and selecting an optimum threshold sensitivity value in response to the step of varying the threshold sensitivity value.
Claim 56
Dependent Claim
24 words
The method for outputting an output digitized signal according to claim 49, wherein the third threshold value is a predetermined value above analog ground.
Claim 57
Dependent Claim
24 words
The method for outputting an output digitized signal according to claim 49, wherein the fourth threshold value is a predetermined value below analog ground.
Claim 58
Dependent Claim
25 words
The method for outputting an output digitized signal according to claim 49, wherein the first threshold value is less sensitive than the third threshold value.
Claim 59
Dependent Claim
25 words
The method for outputting an output digitized signal according to claim 49, wherein the second threshold value is less sensitive than the fourth threshold value.
Claim 60
Dependent Claim
52 words
The method for outputting an output digitized signal according to claim 49, wherein the third digitized signal corresponds to positive peaks of the first derivative signal that exceed both the first and third threshold value and to negative peaks of the first derivative signal that exceed the second and fourth threshold values.
Claim 61
Dependent Claim
38 words
The method for outputting an output digitized signal according to claim 48, wherein the first threshold value being compared to a positive peak is a predetermined value below a preceding positive peak value of the first derivative signal.
Claim 62
Dependent Claim
38 words
The method for outputting an output digitized signal according to claim 48, wherein the second threshold value being compared to a negative peak is a predetermined value above a preceding negative peak value of the first derivative signal.
Claim 63
Independent Claim
138 words
A method for scanning bar code symbols comprising the steps of: scanning a bar code symbol; generating an analog signal corresponding to the scanned bar code symbol; generating a first derivative signal of the analog signal, the first derivative signal having positive and negative peaks; outputting an output digitized signal, the step of outputting including steps for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 64
Independent Claim
138 words
A method for scanning bar code symbols comprising the steps of: scanning a bar code symbol; generating an analog signal corresponding to the scanned bar code symbol; generating a first derivative signal of the analog signal, the first derivative signal having positive and negative peaks; outputting an output digitized signal, the step of outputting including steps for generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; and selecting as the output digitized signal one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal.
Claim 65
Dependent Claim
67 words
The method for scanning bar code symbols according to claim 59, wherein the first digitized signal is selected for wherein the mode selector selects the first sensitivity mode for a bar code with bars and spaces of a first width and selects the second sensitivity mode for a bar code with bars and spaces of a second width, the second width being greater than the first width.
Claim 66
Dependent Claim
52 words
The method for scanning bar code symbols according to claim 59, wherein the first threshold includes a first and second value and wherein positive peaks of the first derivative signal are compared to the first threshold value and negative peaks of the first derivative signal are compared to the second threshold value.
Claim 67
Dependent Claim
52 words
The method for scanning bar code symbols according to claim 61, wherein the second threshold includes a third and fourth value and wherein positive peaks of the first derivative signal are compared to the third threshold value and negative peaks of the first derivative signal are compared to the fourth threshold value.
Claim 68
Dependent Claim
42 words
The method for scanning bar code symbols according to claim 62, wherein the step of selecting includes determining a symbol quality of the scanned bar code symbol; and selecting appropriate threshold sensitivity values for the first, second, third and fourth sensitivity values.
Claim 69
Dependent Claim
54 words
The method for scanning bar code symbols according to claim 62, wherein the step of selecting includes varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and selecting an optimum threshold sensitivity value in response to the step of varying the threshold sensitivity value.
Claim 70
Dependent Claim
23 words
The method for scanning bar code symbols according to claim 62, wherein the third threshold value is a predetermined value above analog ground.
Claim 71
Dependent Claim
23 words
The method for scanning bar code symbols according to claim 62, wherein the fourth threshold value is a predetermined value below analog ground.
Claim 72
Dependent Claim
37 words
The method for scanning bar code symbols according to claim 61, wherein the first threshold value being compared to a positive peak is a predetermined value below a preceding positive peak value of the first derivative signal.
Claim 73
Dependent Claim
37 words
The method for scanning bar code symbols according to claim 61, wherein the second threshold value being compared to a negative peak is a predetermined value above a preceding negative peak value of the first derivative signal.
Claim 74
Independent Claim
123 words
A method for decoding data encoded in a scanned bar code symbol, comprising the steps of: generating an analog signal from a scan of the bar code symbol; generating a first derivative signal of the analog signal; generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; selecting an output digitized signal from one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal; and decoding the output digitized signal.
Claim 75
Independent Claim
123 words
A method for decoding data encoded in a scanned bar code symbol, comprising the steps of: generating an analog signal from a scan of the bar code symbol; generating a first derivative signal of the analog signal; generating a first digitized signal in response to a comparison between the first derivative signal and a first threshold representing a first detection sensitivity; generating a second digitized signal in response to a comparison between the first derivative signal and a second threshold representing a second detection sensitivity; selecting an output digitized signal from one of the first digitized signal and a third digitized signal, the third digitized signal representing the first digitized signal modified by the second digitized signal; and decoding the output digitized signal.
Claim 76
Dependent Claim
57 words
The method of decoding data according to claim 69, wherein the first threshold includes a first and second value and wherein the step of generating a first digitized signal includes comparing positive peaks of the first derivative signal to the first threshold value and comparing negative peaks of the first derivative signal to the second threshold value.
Claim 77
Dependent Claim
57 words
The method of decoding data according to claim 70, wherein the second threshold includes a third and fourth value and wherein the step of generating the second digitized signal includes comparing positive peaks of the first derivative signal to the third threshold value and comparing negative peaks of the first derivative signal to a fourth threshold value.
Claim 78
Dependent Claim
31 words
The method of decoding data according to claim 71, further including the steps of determining a symbol quality of the scanned bar code symbol; and selecting an appropriate threshold sensitivity value.
Claim 79
Dependent Claim
51 words
The method of decoding data according to claim 71, further including the steps of varying a threshold sensitivity value, said threshold sensitivity value corresponding to the first, second, third and fourth threshold values; and selecting an optimum threshold sensitivity value in response to the step of varying the threshold sensitivity value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-03-17 | 2000-09-16 | 2001-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-17 | 2004-09-16 | 2005-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-17 | 2008-09-16 | 2009-03-18 | $7700.00 | Window Closed / Lapsed |