US4730188A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Identification system
Assignee: HID Global Corp
•
Filing: 1985-12-30
•
Granted: 1988-03-08
•
Expires: 2005-12-30
Abstract
Abstract A passive integrated transponder (PIT) is attached to or embedded in an item to be identified. It is excited via an inductive coupling from an interrogator. The PIT responds to the interrogator via the inductive coupling with a signal constituting a stream of data unique to the identified item. The signal is in the form of two different frequencies, a shift from one frequency to the second during a bit cell representing a data "one", and a shift from the second frequency to the first frequency representing a data "zero". The responsive signal is then detected and processed for utilization in a data storage or display device.
Inventors
- 👤 Thomas A. Milheiser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:06
CPC Classifications
G; G06; G06K; G06K19/00; G06K19/06; G06K19/067; G06K19/07; G06K19/0723; G07; G07C; G07C9/00; G07C9/20; G07C9/28; H; H04; H04L; H04L7/00; H04L7/04; H04L7/041; H04L7/044; H04L7/046
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
182 words
An object identification system, comprising: an interrogator comprising means for sending a continuous interrogation signal and means for detecting a responsive identification signal, and a transponder comprising means for detecting said interrogation signal and for transmitting an identification signal in response to said detection, wherein said identification signal extends over a plurality of bit cells of equal length in time, and comprises a preamble portion having a specified number of bit cells and an identification portion having a specified number of bit cells, and a further encoded portion having a specified number of bit cells having a predetermined signal content interposed between said preamble portion and said identification portion; and wherein said preamble and identification portions of said identification signal are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and wherein said further encoded portion is transmitted according to a second format in which said identification signal is transmitted without variation in said transmission parameter for a period at least equal to one bit cell.
Claim 2
Dependent Claim
182 words
An object identification system, comprising: an interrogator comprising means for sending a continuous interrogation signal and means for detecting a responsive identification signal, and a transponder comprising means for detecting said interrogation signal and for transmitting an identification signal in response to said detection, wherein said identification signal extends over a plurality of bit cells of equal length in time, and comprises a preamble portion having a specified number of bit cells and an identification portion having a specified number of bit cells, and a further encoded portion having a specified number of bit cells having a predetermined signal content interposed between said preamble portion and said identification portion; and wherein said preamble and identification portions of said identification signal are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and wherein said further encoded portion is transmitted according to a second format in which said identification signal is transmitted without variation in said transmission parameter for a period at least equal to one bit cell.
Claim 3
Dependent Claim
28 words
The system of claim 1 wherein said interrogator and said transponder are inductively coupled, such that said transponder is powered by said interrogation signal transmitted by said interrogator.
Claim 4
Dependent Claim
16 words
The system of claim 2 wherein said interrogation signal is an RF signal of specified frequency.
Claim 5
Dependent Claim
16 words
The system of claim 3 wherein said bit cells are synchronized to said RF interrogation signal.
Claim 6
Dependent Claim
24 words
The system of claim 4 wherein the frequency of said bit cells is an integer factor of the frequency of said RF interrogation signal.
Claim 7
Independent Claim
18 words
The system of any one of claims 1-5 wherein said identification signal is a frequency shift keyed signal.
Claim 8
Dependent Claim
48 words
The system of claim 6 wherein said frequency shift keyed identification signal is varied between first and second frequencies substantially at the center of said bit cells, the direction of said variation in a given bit cell encoding a data value to be sent during said bit cell.
Claim 9
Dependent Claim
24 words
The system of claim 5 wherein the frequency of said bit cells is derived from the RF interrogation signal by successive integer division thereof.
Claim 10
Dependent Claim
16 words
The system of claim 8 wherein said integer division is performed by cascaded flip-flop circuit elements.
Claim 11
Independent Claim
26 words
The system of any of of claims 1-5 wherein said identification signal comprises a sequence of digital bits, said sequence being stored in solid-state memory means.
Claim 12
Dependent Claim
14 words
The system of claim 10 wherein said solid-state memory means is a diode matrix.
Claim 13
Dependent Claim
22 words
The system of claim 1, wherein in said first format said transmission parameter is varied in the center of each bit cell.
Claim 14
Dependent Claim
11 words
The system of claim 1, wherein said transmission parameter is frequency.
Claim 15
Dependent Claim
52 words
The system of claim 13, wherein in the first format the frequency of the identification signal is varied from a relatively low to a relatively high frequency during a bit cell to transmit a data zero and from a relatively high frequency to a relatively low frequency to transmit a data one.
Claim 16
Dependent Claim
182 words
A transponder for use in an object identification system of the type comprising an interrogator comprising means for sending a continuous interrogation signal and means for detecting a responsive identification signal, said transponder comprising means for detecting said interrogation signal and for transmitting an identification signal in response to said detection, wherein said identification signal extends over a plurality of bit cells of equal length in time, and comprises a preamble portion having a specified number of bit cells, a data portion hving a specified number of bit cells, and a further portion having a specified number of bit cells each having a predetermined signal content interposed between said preamble portion and said data portion, and wherein said preamble and data portions are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and said further portion is transmitted according to a second format in which the identification signal is transmitted without variation in said transmission parameter for a period at least equal to one bit cell.
Claim 17
Dependent Claim
182 words
A transponder for use in an object identification system of the type comprising an interrogator comprising means for sending a continuous interrogation signal and means for detecting a responsive identification signal, said transponder comprising means for detecting said interrogation signal and for transmitting an identification signal in response to said detection, wherein said identification signal extends over a plurality of bit cells of equal length in time, and comprises a preamble portion having a specified number of bit cells, a data portion hving a specified number of bit cells, and a further portion having a specified number of bit cells each having a predetermined signal content interposed between said preamble portion and said data portion, and wherein said preamble and data portions are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and said further portion is transmitted according to a second format in which the identification signal is transmitted without variation in said transmission parameter for a period at least equal to one bit cell.
Claim 18
Dependent Claim
30 words
The transponder of claim 15 wherein said transponder includes means for inductively coupling to said interrogator, such that said transponder is powered by said interrogation signal transmitted by said interrogator.
Claim 19
Dependent Claim
16 words
The transponder of claim 16 wherein said interrogation signal is an RF signal of specified frequency.
Claim 20
Dependent Claim
16 words
The transponder of claim 17 wherein said bit cells are synchronized to said RF interrogation signal.
Claim 21
Dependent Claim
24 words
The transponder of claim 18 wherein the frequency of said bit cells is an integer factor of the frequency of said RF interrogation signal.
Claim 22
Dependent Claim
18 words
The transponder of any one of claims 15-19 wherein said identification signal is a frequency shift keyed signal.
Claim 23
Dependent Claim
48 words
The transponder of claim 20 wherein said frequency shift keyed identification signal is varied between first and second frequencies substantially at the center of said bit cells, the direction of said variation in a given bit cell encoding a data value to be sent during said bit cell.
Claim 24
Dependent Claim
24 words
The transponder of claim 19 wherein the frequency of said bit cells is derived from the RF interrogation signal by successive integer division thereof.
Claim 25
Dependent Claim
16 words
The transponder of claim 22 wherein said integer division is performed by cascaded flip-flop circuit elements.
Claim 26
Dependent Claim
26 words
The transponder of any one of claims 15-19 wherein said identification signal comprises a sequence of digital bits, said sequence being stored in solid-state memory means.
Claim 27
Dependent Claim
22 words
The transponder of claim 15, wherein in said first format said transmission parameter is varied in the center of each bit cell.
Claim 28
Dependent Claim
11 words
The transponder of claim 15, wherein said transmission parameter is frequency.
Claim 29
Dependent Claim
48 words
The transponder of claim 26, wherein the frequency of the identification signal is varied from a relatively low to a relatively high frequency during a bit cell to transmit a data zero, and from a relatively high frequency to a relatively low frequency to transmit a data one.
Claim 30
Dependent Claim
166 words
Method for identifying objects, comprising the steps of: emitting a continuous interrogation signal from an interrogator; detecting said interrogation signal at a transponder in the vicinity of said interrogator; transmitting an encoded identification signal from said transponder to said interrogator; and receiving and decoding said encoded identification signal at said interrogator; wherein said identification signal includes a first preamble portion, a last identification portion, and a further portion interposed between said first and last portions, wherein said preamble and identification portions each have a number of equally-spaced bit cells, and said further portion comprises a number of bit cells each of predetermined signal content and wherein said preamble and identification portions are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and said further portion is transmitted according to a second format in which said transmission parameter is not varied for a period at least equal to one bit cell.
Claim 31
Dependent Claim
166 words
Method for identifying objects, comprising the steps of: emitting a continuous interrogation signal from an interrogator; detecting said interrogation signal at a transponder in the vicinity of said interrogator; transmitting an encoded identification signal from said transponder to said interrogator; and receiving and decoding said encoded identification signal at said interrogator; wherein said identification signal includes a first preamble portion, a last identification portion, and a further portion interposed between said first and last portions, wherein said preamble and identification portions each have a number of equally-spaced bit cells, and said further portion comprises a number of bit cells each of predetermined signal content and wherein said preamble and identification portions are transmitted according to a first format in which a signal transmission parameter is varied between first and second values during each of said bit cells, and said further portion is transmitted according to a second format in which said transmission parameter is not varied for a period at least equal to one bit cell.
Claim 32
Dependent Claim
23 words
The method of claim 28 wherein said step of receiving the interrogation signal includes the step of receiving power from the interrogation signal.
Claim 33
Dependent Claim
36 words
The method of claim 28 wherein said step of transmitting the encoded identification signal includes the step of generating a clock signal derived from the interrogation signal and synchronizing the portions of the identification signal thereto.
Claim 34
Dependent Claim
23 words
The method of claim 30 wherein said clock signal is derived from said interrogation signal by integer division thereof in flip-flop circuit elements.
Claim 35
Dependent Claim
34 words
The method of claim 28 wherein said identification signal is a frequency-shift-keyed signal according to which the data transmitted as part of said identification signal is encoded by variation of the frequency of transmission.
Claim 36
Dependent Claim
25 words
The method of claim 32 wherein said variation is between first and second frequencies, each being integral factors of the frequency of the interrogation signal.
Claim 37
Dependent Claim
19 words
The method of claim 33 wherein said identification signal is divided into bit cells synchronized to said identification signal.
Claim 38
Dependent Claim
17 words
The method of claim 34 wherein said bit cells are defined by division of said interrogation signal.
Claim 39
Dependent Claim
39 words
The method of claim 35 wherein said variation of the frequency of the signal occurs substantially at the center of each bit cell, and its direction is responsive to the data value to be encoded during the bit cell.
Claim 40
Dependent Claim
22 words
The system of claim 28, wherein in said first format said transmission parameter is varied in the center of each bit cell.
Claim 41
Dependent Claim
11 words
The method of claim 28, wherein said transmission parameter is frequency.
Claim 42
Dependent Claim
48 words
The system of claim 38, wherein the frequency of the identification signal is varied from a relatively low to a relatively high frequency during a bit cell to transmit a data zero and from a relatively high frequency to a relatively low frequency to transmit a data one.
References Cited (Backward Citations)
US3137847A
Cited
US3144017A
Cited
US3022492A
Cited
US3128744A
Cited
US3313301A
Cited
US3299424A
Cited
US3440633A
Cited
US3369525A
Cited
US3427614A
Cited
US3557758A
Cited
US3541995A
Cited
US3545405A
Cited
US3878322A
Cited
US4079414A
Cited
US3757035A
Cited
US3689885A
Cited
US3739279A
Cited
US3933612A
Cited
US3803571A
Cited
US3752960A
Cited
US3816709A
Cited
US3859624A
Cited
US3890581A
Cited
US3820545A
Cited
US3898619A
Cited
US4262632A
Cited
US3944928A
Cited
US4040053A
Cited
US4053836A
Cited
US4075632A
Cited
US4065753A
Cited
US4087791A
Cited
US3964024A
Cited
US4068232A
Cited
US4114151A
Cited
US4196418A
Cited
US4209783A
Cited
US4187509A
Cited
US4129855A
Cited
US4233964A
Cited
US4313033A
Cited
US4368439A
Cited
US4242663A
Cited
DE2919753A1
Cited
US4350883A
Cited
US4333072A
Cited
US4345253A
Cited
US4485347A
Cited
US4494553A
Cited
US4447909A
Cited
US4517563A
Cited
US4463353A
Cited
US4388524A
Cited
US4556883A
Cited
US4510495A
Cited
US4596985A
Cited
US4630044A
Cited
US4525713A
Cited
US4602253A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-08 | 1991-09-07 | 1992-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-08 | 1995-09-07 | 1996-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-08 | 1999-09-07 | 2000-03-08 | $7700.00 | Window Closed / Lapsed |