US4652731A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and device for detecting bar codes
Assignee: Thales SA
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Filing: 1985-08-06
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Granted: 1987-03-24
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Expires: 2005-08-06
Abstract
Abstract A process of detecting bar codes constituted by bars having a height H and a width D and presenting flaws of a height A, which comprises the steps of summing the signals issuing from detectors of identical rank which belong to at least two rows of N detectors having a spacing pitch smaller than or equal to D/2, said rows being perpendicular to said codes so that at least one of the distances between said rows is greater than A, and comparing the sum signal thus obtained to a decision threshold to obtain a "code present" or "code absent" signal while eliminating any flaws possibly present in said codes.
Inventors
- 👤 Jacques Chautemps
- 👤 Jean L. Coutures
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:21
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
109 words
A process of detecting bar codes constituted by bars having a height H and a width D and presenting flaws of a height A, which comprises the steps of summing the signals issuing from detectors of identical rank which belong to at least two rows of N detectors having a spacing pitch smaller than or equal to D/2, said rows being perpendicular to said codes so that at least one of the distances between said rows is greater than A, and comparing the sum signal thus obtained to a decision threshold to obtain a "code present" or "code absent" signal while eliminating any flaws possibly present in said codes.
Claim 2
Dependent Claim
109 words
A process of detecting bar codes constituted by bars having a height H and a width D and presenting flaws of a height A, which comprises the steps of summing the signals issuing from detectors of identical rank which belong to at least two rows of N detectors having a spacing pitch smaller than or equal to D/2, said rows being perpendicular to said codes so that at least one of the distances between said rows is greater than A, and comparing the sum signal thus obtained to a decision threshold to obtain a "code present" or "code absent" signal while eliminating any flaws possibly present in said codes.
Claim 3
Dependent Claim
40 words
A detection process according to claim 1, wherein said decision threshold is at most equal to 50% of the sum signal obtained, when all the detectors of identical rank detect a white level corresponding to absence of codes and flaws.
Claim 4
Dependent Claim
20 words
The detection process of claim 2, wherein said decision threshold is comprised between 35 and 45% of said sum signal.
Claim 5
Dependent Claim
102 words
A device for carrying out the process according to claim 1, which comprises at least two rows of N detectors having a spacing pitch smaller than or equal to D/2, said rows being perpendicular to said codes in such a manner that at least one of the distances between said rows is greater than A, means for summing and reading the signals issuing from detectors of identical rank, and means for comparing the thus-obtained sum signals to a decision threshold and for supplying a signal indicating the presence or the absence of codes, while eliminating the flaws possibly present in said codes.
Claim 6
Dependent Claim
14 words
A device according to claim 4, wherein said detectors are photodiodes or photo-MOS transistors.
Claim 7
Dependent Claim
83 words
A device according to claim 4, wherein said means for summing and reading said signals issuing from detectors of identical rank are constituted by arrays of switches associated to said detector rows, each switch of any one of said arrays being connected respectively to one detector and to an output line connected through a current voltage amplifier to one of the input terminals of a summer, and by a logic shift register addressing sequentially the switches of identical rank in the different arrays.
Claim 8
Dependent Claim
64 words
A device according to claim 4, wherein said means for summing and reading the signals issuing from detectors of identical rank are constituted by arrays of switches associated to said detector rows, each switch of any one of said arrays being connected respectively to a current/voltage amplifier, and by a logic shift register addressing sequentially the switches of identical rank in the different arrays.
Claim 9
Dependent Claim
14 words
The device according to claim 6, wherein said switches are constituted by MOS transistors.
Claim 10
Dependent Claim
14 words
The device according to claim 7, wherein said switches are constituted by MOS transistors.
Claim 11
Dependent Claim
69 words
A device acording to claim 4, wherein said means for summing and reading the signals issuing from detectors of identical rank are constituted by a charge-transfer shift register with N stages, having parallel inputs and a series output, and by a charge/voltage conversion stage disposed at the output of said charge-transfer shift register, each stage of said register being connected to detectors of identical rank of the different rows.
Claim 12
Dependent Claim
74 words
A device according to claim 4, wherein said means for summing and reading the signal issuing from detectors of identical rank are constituted by charge-transfer shift registers having N stages, parallel inputs and a series output, each stage being associated to one row of detectors, and by a common summing and charge/tension conversion stage disposed at the output of said charge-transfer shift registers, the different charge-transfer shift registers being controlled by identical control signals.
Claim 13
Dependent Claim
23 words
A device according to claim 4, further comprising means for injecting a driving charge into the different stages of said charge-transfer shift register(s).
Claim 14
Dependent Claim
36 words
The device according to claim 12, wherein said means for injecting a driving charge are constituted by a charge injection stage which injects in series the driving charge into the stages of said charge-transfer shift register(s).
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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) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |