US5608200A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of collecting and adjusting bar code data from a laser bar code reader
Assignee: Symbol Technologies LLC
•
Filing: 1994-11-28
•
Granted: 1997-03-04
•
Expires: 2014-11-28
Abstract
Abstract A method is disclosed for processing bar code data obtained from a bar code label including large and small bars. A light source such as a laser beam scans across the symbol on a bar code label. Light reflected from the bar code label is collected as the light source scans across the label. The collected light varies in intensity as the light source scans across the label. An electrical signal is generated which is indicative of the amplitude of the light collected in the collecting step. The electrical signal is sampled at a predetermined data rate to produce a sequence of samples representative of the electrical signal. A sequence of samples is stored in a memory. These stored samples include label space values (LSA's). The samples also include label bar values (LBA's) which include large bar values and small bar values. The sequence of samples is decoded. The label space reflectance (LSR) is determined by dividing the product of the calibration space reflectance (CSR) and a label space value (LSA) by the calibration space average (CSA). The disclosed method also provides for the normalization of label bar values (LBA's).
Inventors
- 👤 Stephen H. Le Goff
- 👤 Ralph Rosa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 03:58
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10851; G06K19/00; G06K19/06; G06K19/06009; G06K19/06018; G06K19/06028; G06K5/00; G06K7/10554; G06K7/10564; G06K7/10584; G06K7/10594; G06K7/10603; G06K7/10613; G06K7/10623; G06K7/10792; G06K7/10801; G06K7/10881; G06K7/14
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
199 words
A method of processing bar code data obtained from an unknown bar code label including large and small bars, the method comprising the steps of: establishing standard values of calibration space reflectance (CSR) and calibration space average (CSA) from a standard, ideal bar code label; scanning a light source across the unknown bar code label; collecting light which is reflected from the unknown bar code label as the light source scans across the label thus producing collected light, the light thus collected varying in intensity as the light source scans across the label; generating an electrical signal indicative of the amplitude of the light collected in the collecting step; sampling the electrical signal at a predetermined data rate to produce a sequence of samples representative of the electrical signal; storing the sequence of samples in a memory, the samples including label space values (LSA's) and label bar values (LBA's) which include large bar values and small bar values; decoding the sequence of samples; and determining a label space reflectance (LSR) value of the unknown bar code label by dividing the product of the calibration space reflectance (CSR) and a label space value (LSA) by the calibration space average (CSA).
Claim 2
Independent Claim
199 words
A method of processing bar code data obtained from an unknown bar code label including large and small bars, the method comprising the steps of: establishing standard values of calibration space reflectance (CSR) and calibration space average (CSA) from a standard, ideal bar code label; scanning a light source across the unknown bar code label; collecting light which is reflected from the unknown bar code label as the light source scans across the label thus producing collected light, the light thus collected varying in intensity as the light source scans across the label; generating an electrical signal indicative of the amplitude of the light collected in the collecting step; sampling the electrical signal at a predetermined data rate to produce a sequence of samples representative of the electrical signal; storing the sequence of samples in a memory, the samples including label space values (LSA's) and label bar values (LBA's) which include large bar values and small bar values; decoding the sequence of samples; and determining a label space reflectance (LSR) value of the unknown bar code label by dividing the product of the calibration space reflectance (CSR) and a label space value (LSA) by the calibration space average (CSA).
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the large bar values comprise tall bar values and the small bar values comprise short bar values.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein the large bar values comprise wide bar values and the small bar values comprise narrow bar values.
Claim 5
Dependent Claim
47 words
The method of claim 1 further comprising the steps of: retrieving a calibration space average (CSA) from a first memory; retrieving a label space value (LSA) from a second memory; determining a multiplier, MULTIPLR, by dividing the calibration space average (CSA) by the label space value (LSA).
Claim 6
Dependent Claim
55 words
The method of claim 4 further comprising the step of: retrieving a label bar value (LBA) from the second memory to provide a retrieved label bar value (LBA); modifying the retrieved label bar value (LBA) by multiplying the retrieved label bar value (LBA) by the multiplier, MULTIPLR, to produce a modified label bar value (LBA').
Claim 7
Dependent Claim
39 words
The method of claim 5 further comprising the step of: normalizing the modified label bar value (LBA') by performing the following operation on the modified label bar value (LBA') ##EQU4## thus producing a normalized modified label bar value, NLBA.
Claim 8
Dependent Claim
20 words
The method of claim 6 further comprising the step of converting the normalized modified label bar value, NLBA, to reflectance.
Claim 9
Independent Claim
147 words
A method for calibrating a laser bar code scanner for reading bar code labels comprising the steps of: scanning a calibration standard label with a laser scanner and recording reflectivity characteristics of spaces end bars of the scanned label over a scanned range in a first memory; dividing the scanned range into a plurality of equal time increments and associating the recorded reflectivity characteristics with a corresponding time increment; scanning a label to be read with the scanner and storing reflectivity characteristics of the read label in a second memory; associating the reflectivity characteristics of the read label with corresponding time increments obtained by dividing a range of scanning of the scanner into the plurality of equal time increments; and comparing each reflectivity characteristic of the read label on a time increment basis to each recorded reflectivity characteristic of the calibration label for interpreting the read label.
Claim 10
Independent Claim
147 words
A method for calibrating a laser bar code scanner for reading bar code labels comprising the steps of: scanning a calibration standard label with a laser scanner and recording reflectivity characteristics of spaces end bars of the scanned label over a scanned range in a first memory; dividing the scanned range into a plurality of equal time increments and associating the recorded reflectivity characteristics with a corresponding time increment; scanning a label to be read with the scanner and storing reflectivity characteristics of the read label in a second memory; associating the reflectivity characteristics of the read label with corresponding time increments obtained by dividing a range of scanning of the scanner into the plurality of equal time increments; and comparing each reflectivity characteristic of the read label on a time increment basis to each recorded reflectivity characteristic of the calibration label for interpreting the read label.
References Cited (Backward Citations)
US4251798A
Cited
US4360798A
Cited
US4508686A
Cited
US4705939A
Cited
US4860226A
Cited
US5218190A
Cited
US5369264A
Cited
US5235056A
Cited
US5406062A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-03-03 | 2000-09-02 | 2001-03-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-03 | 2004-09-02 | 2005-03-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-03 | 2008-09-02 | 2009-03-04 | $7700.00 | Window Closed / Lapsed |