US6471126B2
Expired / Lapsed
US
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Method and apparatus for reading invisible symbol
Assignee: Toshiba Corp
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Filing: 2001-01-02
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Granted: 2002-10-29
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Expires: 2021-01-02
Abstract
Abstract An invisible symbol reading apparatus includes a heating unit for heating an invisible symbol formed on a sample and containing a material which emits infrared light when heated, a detecting unit for detecting infrared light emitted from the invisible symbol, and an arithmetic operation unit for binarizing a detection signal from the detecting unit. The arithmetic operation unit calculates a differential coefficient of the detection signal, that corresponds to a position on the sample. On the basis of upper and lower threshold values set for the differential coefficient, the arithmetic operation unit determines a maximum value of the differential coefficient in a region exceeding the upper threshold value and a minimum value of the differential coefficient in a region smaller than the lower threshold value. The arithmetic operation unit binarizes the detection signal by using the maximum or minimum value as a leading or trailing edge of a binary function.
Inventors
- 👤 Taeko I. Urano
- 👤 Kenji Sano
- 👤 Hideo Nagai
- 👤 Tomokazu Domon
- 👤 Hironori Fukuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:40
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/14
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
99 words
A method for reading an invisible symbol comprising the steps of: exciting molecular vibration of an invisible symbol formed on a sample and containing a material which emits infrared light when heated; detecting infrared light emitted from the invisible symbol; providing a differential coefficient of a detection signal corresponding to a position on the sample; determining, based on threshold values set for the differential coefficient, alternating maximum and minimum values of differential coefficients outside said threshold values; and binarizing the detection signal by using the maximum or minimum value as a leading or trailing edge of a binary function.
Claim 2
Independent Claim
99 words
A method for reading an invisible symbol comprising the steps of: exciting molecular vibration of an invisible symbol formed on a sample and containing a material which emits infrared light when heated; detecting infrared light emitted from the invisible symbol; providing a differential coefficient of a detection signal corresponding to a position on the sample; determining, based on threshold values set for the differential coefficient, alternating maximum and minimum values of differential coefficients outside said threshold values; and binarizing the detection signal by using the maximum or minimum value as a leading or trailing edge of a binary function.
Claim 3
Dependent Claim
28 words
The method according to claim 1 , wherein the step of detecting infrared light emitted from the invisible symbol is performed in a process of cooling the sample.
Claim 4
Dependent Claim
42 words
The method according to claim 1 , wherein the invisible symbol is a linear barcode, a basic width of the linear barcode is calculated from the binary function, and the binary function is corrected to an integral multiple of the basic width.
Claim 5
Dependent Claim
44 words
The method according to claim 1 , wherein the invisible symbol is a linear barcode, a basic width of the linear barcode is calculated by detecting a reference code pattern, and a data character is read on the basis of the calculated basic width.
Claim 6
Dependent Claim
32 words
The method according to claim 1 , wherein a signal level of an underlying substrate is used as a signal level of background to correct a signal level of the invisible symbol.
Claim 7
Dependent Claim
20 words
The method according to claim 1 , wherein the invisible symbol is made from a polymer containing a cyano group.
Claim 8
Dependent Claim
17 words
The method according to claim 1 , wherein the sample is heated to 60 to 100° C.
Claim 9
Dependent Claim
19 words
The method according to claim 1 , wherein the molecular vibration of the invisible symbol is excited by heating.
Claim 10
Dependent Claim
20 words
The method according to claim 1 , wherein the molecular vibration of the invisible symbol is excited by light irradiation.
Claim 11
Independent Claim
130 words
An apparatus for reading an invisible symbol comprising: a unit configured to excite molecular vibration of a material of the invisible symbol, the invisible symbol formed of a sample and containing a material which emits infrared light when heated; a detector configured to detect infrared light emitted from the invisible symbol; and an arithmetic operation unit configured to binarize a detection signal from said detector; wherein said arithmetic operation unit calculates differential coefficients of the detection signal corresponding to positions on the sample, determines, based on threshold values set for the differential coefficients, alternating maximum and minimum values of the differential coefficient in regions outside the threshold values, and binarizes the detection signal by using the maximum or minimum value as a leading or trailing edge of a binary function.
Claim 12
Independent Claim
130 words
An apparatus for reading an invisible symbol comprising: a unit configured to excite molecular vibration of a material of the invisible symbol, the invisible symbol formed of a sample and containing a material which emits infrared light when heated; a detector configured to detect infrared light emitted from the invisible symbol; and an arithmetic operation unit configured to binarize a detection signal from said detector; wherein said arithmetic operation unit calculates differential coefficients of the detection signal corresponding to positions on the sample, determines, based on threshold values set for the differential coefficients, alternating maximum and minimum values of the differential coefficient in regions outside the threshold values, and binarizes the detection signal by using the maximum or minimum value as a leading or trailing edge of a binary function.
Claim 13
Dependent Claim
48 words
The apparatus according to claim 10 , wherein said heater heats the sample is installed in a position apart from said detector, and said apparatus further comprises a conveyor configured to move the sample from a heating position of said heater to a detection position of said detector.
Claim 14
Dependent Claim
22 words
The apparatus according to claim 10 , further comprising a controller configured to turn off said heater before detection by said detector.
Claim 15
Dependent Claim
40 words
The apparatus according to claim 10 , further comprising: an optical modulator configured to optically modulate the infrared light emitted from the invisible symbol; and said detector comprising a phase detector configured to detect a phase of a detection signal.
Claim 16
Dependent Claim
31 words
The apparatus according to claim 10 , further comprising a bandpass infrared filter for transmitting infrared light in a specific wavelength region of the infrared light emitted from the invisible symbol.
Claim 17
Dependent Claim
23 words
The apparatus according to claim 13 , wherein said bandpass infrared filter transmits infrared light near 4.5 μm peculiar to a cyano group.
Claim 18
Dependent Claim
13 words
The apparatus according to claim 10 , further comprising a calcium fluoride lens.
Claim 19
Dependent Claim
12 words
The apparatus according to claim 10 , further comprising a Cassegrain lens.
Claim 20
Dependent Claim
16 words
The apparatus according to claim 10 , wherein said detector is a mercury cadmium tellurium detector.
Claim 21
Dependent Claim
15 words
The apparatus according to claim 10 , wherein said detector forms a focal plane array.
Claim 22
Dependent Claim
31 words
The apparatus according to claim 19 , wherein an element constructing said focal plane array is made of a material selected from the group consisting of platinum silicide and indium antimony.
Claim 23
Dependent Claim
25 words
The apparatus according to claim 10 , wherein the unit configured to excite molecular vibration of a material of the invisible symbol is a heater.
Claim 24
Dependent Claim
26 words
The apparatus according to claim 10 , wherein the unit configured to excite molecular vibration of a material of the invisible symbol is a light source.
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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) | 2005-10-28 | 2006-04-29 | 2006-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-10-28 | 2010-04-29 | 2010-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-10-28 | 2014-04-29 | 2014-10-29 | $7700.00 | Window Closed / Lapsed |