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US5539393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Information system
Assignee: Esel-Krabbe Systems AS
•
Filing: 1992-03-20
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Granted: 1996-07-23
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Expires: 2012-03-20
Abstract
Abstract An information system comprises a master station (2, 10) controlling information to be displayed on a number of information units (30, 40) arranged remotely from said master station. The master station broadcasts instructions by modulated infrared signals, and these signals are detected by a photodiode within each information unit (30, 40), said information unit also comprising a receiver and logic circuitry. The information unit (30, 40) further comprises an emitter diode in order that it is capable of acknowledging the receipt of instructions. Information is presented on LCD-type displays, e.g. digits, a graphic field, or other information fields, all being implemented in LCD-type displays. The display units are, in particular, applicable in shops or warehouses, e.g. supermarkets, where a display unit may be arranged adjacent each item of merchandise, serving the purpose of displaying e.g. the unit price on the information unit. The system according to the invention permits an automatic updating of prices and guarantees a reliable functioning through the facility of requesting verification signals to be transmitted from the individual information units.
Inventors
- 👤 Jesper M. Barfod
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 15:37
CPC Classifications
G; G06; G06Q; G06Q30/00; G06Q30/02; G06Q10/00; G06Q10/08; G06Q10/087; G06Q10/0872; G06Q10/08724; G06Q10/08726; G06Q30/0283
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
281 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting said verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 2
Independent Claim
281 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting said verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 3
Independent Claim
287 words
A system for displaying information, said system comprising: a master computer including storage means for storing instruction signals and verification signals, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of a specific instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said master computer comparing said verification signal received by said receiving means thereof with said verification signals stored in said storage means for verifying the proper detection of said specific instruction signal by the intended information unit.
Claim 4
Independent Claim
287 words
A system for displaying information, said system comprising: a master computer including storage means for storing instruction signals and verification signals, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of a specific instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said master computer comparing said verification signal received by said receiving means thereof with said verification signals stored in said storage means for verifying the proper detection of said specific instruction signal by the intended information unit.
Claim 5
Dependent Claim
52 words
The system according to claim 2, wherein said digital memory means of each information unit stores a specific address corresponding to a portion of said specific instruction signal for deciding whether an infrared signal emitted from said infrared signal transmitting means of said master computer is addressed to the particular information unit.
Claim 6
Dependent Claim
31 words
The system according to claim 3, wherein each information unit responds to instruction signals specifically addressed to the unit and also to instruction signals not specifically addressed to any information unit.
Claim 7
Dependent Claim
42 words
The system according to claim 3, wherein said digital memory means of each information unit stores a group address, which is common to a number of information units, and responds to instruction signals addressed to the group identified by said group address.
Claim 8
Dependent Claim
21 words
The system according to claim 2, wherein said specific instruction signal selectively includes an instruction to turn off said display means.
Claim 9
Dependent Claim
21 words
The system according to claim 2, wherein said specific instruction signal selectively includes an instruction to turn on said display means.
Claim 10
Independent Claim
282 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, timer means included in said housing and operatively connected to said digital memory means and said display means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said displaying means thereof by turning off said display means for a predetermined period of time determined by said timer means in response to the detection of an instruction signal including an instruction to turn off said display means transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 11
Independent Claim
282 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, timer means included in said housing and operatively connected to said digital memory means and said display means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said displaying means thereof by turning off said display means for a predetermined period of time determined by said timer means in response to the detection of an instruction signal including an instruction to turn off said display means transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 12
Dependent Claim
19 words
The system according to claim 8, wherein said predetermined period of time is encoded into said digital memory means.
Claim 13
Dependent Claim
33 words
The system according to claim 8, wherein said predetermined period of time is modified by an instruction signal including an instruction to modify the predetermined period of time transmitted from said master computer.
Claim 14
Independent Claim
308 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, power supply means included in said housing and operatively connected to said digital memory means and said display means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said displaying means thereof by placing said power supply means into a power-down mode in response to the detection of a first instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a first verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 15
Independent Claim
308 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, power supply means included in said housing and operatively connected to said digital memory means and said display means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said displaying means thereof by placing said power supply means into a power-down mode in response to the detection of a first instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a first verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 16
Dependent Claim
119 words
The system according to claim 11 wherein said digital memory means of each information unit controls the displaying of said displaying means thereof by placing said power supply means into a power-up mode in response to the detection of a second instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controls said infrared signal emitting means for emitting a second verification signal to said infrared signal receiving means of said master computer, and wherein said infrared signal receiving means of said master computer, upon receipt of said second verification signal by said master computer, confirms proper detection of said second instruction signal by said information unit.
Claim 17
Dependent Claim
42 words
The system according to claim 2, wherein said information unit stores status information in said digital memory, and wherein said information unit emits said status information upon the receipt of an instruction signal including a special interrogation instruction from said master computer.
Claim 18
Dependent Claim
39 words
The system according to claim 2, said information unit further being provided with input terminals for connection to external signalling equipment for receiving signals input through said input terminals and for storing said signals in said digital memory means.
Claim 19
Dependent Claim
59 words
The system according to claim 2, wherein said infrared signal transmitting means of said master computer transmits said specific instruction signal transferred from said storage means constituted by an instruction in combination with a number identifying said instruction, and wherein each information unit responds to the receipt of said instruction signal by retransmitting said number constituting said verification signal.
Claim 20
Dependent Claim
25 words
The system according to claim 2, wherein said master computer comprises a transponder including said infrared signal transmitting means and said infrared signal receiving means.
Claim 21
Dependent Claim
20 words
The system according to claim 16, wherein said transponder comprises at least one diode constituting said infrared signal transmitting means.
Claim 22
Dependent Claim
20 words
The system according to claim 16, wherein said transponder comprises at least one photodiode constituting said infrared signal receiving means.
Claim 23
Dependent Claim
62 words
The system according to claim 2, wherein said information unit comprises carrier wave stage means for detecting a carrier wave and a demodulator means, and wherein said information unit supplies electric power to said demodulator means upon detection of a carrier wave by said carrier wave stage means for a period of time allowing said demodulator means to receive said instruction signal.
Claim 24
Dependent Claim
59 words
The system according to claim 19, wherein said information unit further comprises input threshold detector means for detecting a powerful infrared signal, even at times when said carrier wave stage is unpowered, and for responding to said powerful signal by powering said carrier wave stage for a period of time allowing said demodulator means to receive said instruction signal.
Claim 25
Dependent Claim
12 words
The system according to claim 2, wherein said information unit is battery-powered.
Claim 26
Independent Claim
418 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit, and a portable unit comprising a housing, infrared signal transmission means for transmitting an infrared signal, said infrared signal transmission means being included in said portable unit housing, manual activation means included in said portable unit housing and operatively connected to said infrared signal transmission means for activating said infrared signal transmission means for transmitting an infrared signal, and directional delimiting means for directional delimiting said infrared signal transmitting from said infrared transmission means to a predetermined angular region centered around a longitudinal axis of said portable unit in order that said infrared signal transmitted from said infrared signal transmission means be directed from said portable unit within said predetermined angular region so as to prevent the information units located outside said angular region from detecting said infrared signal emitted from said infrared signal transmission means of said portable unit.
Claim 27
Independent Claim
418 words
A system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit, and a portable unit comprising a housing, infrared signal transmission means for transmitting an infrared signal, said infrared signal transmission means being included in said portable unit housing, manual activation means included in said portable unit housing and operatively connected to said infrared signal transmission means for activating said infrared signal transmission means for transmitting an infrared signal, and directional delimiting means for directional delimiting said infrared signal transmitting from said infrared transmission means to a predetermined angular region centered around a longitudinal axis of said portable unit in order that said infrared signal transmitted from said infrared signal transmission means be directed from said portable unit within said predetermined angular region so as to prevent the information units located outside said angular region from detecting said infrared signal emitted from said infrared signal transmission means of said portable unit.
Claim 28
Dependent Claim
52 words
The system according to claim 22, wherein said digital memory means of each information unit stores a specific address corresponding to a portion of said specific instruction signal for deciding whether an infrared signal emitted from said infrared signal transmitting means of said master computer is addressed to the particular information unit.
Claim 29
Dependent Claim
31 words
The system according to claim 23, wherein each information unit responds to instruction signals specifically addressed to the unit and also to instruction signals not specifically addressed to any information unit.
Claim 30
Dependent Claim
287 words
An information unit of a system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, and a plurality of individual information units for the displaying of individual information, said information unit comprising: a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, and said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 31
Dependent Claim
287 words
An information unit of a system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, and a plurality of individual information units for the displaying of individual information, said information unit comprising: a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, and said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit.
Claim 32
Dependent Claim
52 words
The system according to claim 25, wherein said digital memory means of each information unit stores a specific address corresponding to a portion of said specific instruction signal for deciding whether an infrared signal emitted from said infrared signal transmitting means of said master computer is addressed to the particular information unit.
Claim 33
Dependent Claim
31 words
The system according to claim 26, wherein each information unit responds to instruction signals specifically addressed to the unit and also to instruction signals not specifically addressed to any information unit.
Claim 34
Dependent Claim
419 words
A portable unit of a system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit, said portable unit comprising: a housing, infrared signal transmission means for transmitting an infrared signal, said infrared signal transmission means being included in said portable unit housing, manual activation means included in said portable unit housing and operatively connected to said infrared signal transmission means for activating said infrared signal transmission means for transmitting an infrared signal, and directional delimiting means for directional delimiting said infrared signal transmitting from said infrared transmittal means to a predetermined angular region centered around a longitudinal axis of said portable unit in order that said infrared signal transmitted from said infrared signal transmission means be directed from said portable unit within said predetermined angular region so as to prevent that information units located outside said angular region detects said infrared signal emitted from said infrared signal transmission means.
Claim 35
Dependent Claim
419 words
A portable unit of a system for displaying information, said system comprising: a master computer including storage means for storing an instruction signal and a verification signal, infrared signal transmitting means operatively connected to said storage means for transmitting an infrared signal, and infrared signal receiving means operatively connected to said storage means for receiving an infrared signal, a plurality of individual information units for the displaying of individual information, each information unit comprising a housing, displaying means included in said housing and exposed at said housing for displaying said individual information, digital memory means included in said housing and operatively connected to said displaying means, infrared signal detecting means for detecting an infrared signal transmitted from said infrared signal transmitting means of said master computer, said infrared signal detecting means being included in said housing and being operatively connected to said digital memory means, and infrared signal emitting means for emitting an infrared signal to said infrared signal receiving means of said master computer, said infrared signal emitting means being included in said housing and being operatively connected to said digital memory means, said digital memory means of each information unit controlling the displaying of said individual information of said displaying means thereof in response to the detection of said instruction signal transmitted from said infrared signal transmitting means of said master computer and received by said infrared signal detecting means, and controlling said infrared signal emitting means for emitting a verification signal to said infrared signal receiving means of said master computer, and said infrared signal receiving means of said master computer, upon receipt of said verification signal by said master computer, confirming proper detection of said instruction signal by said information unit, said portable unit comprising: a housing, infrared signal transmission means for transmitting an infrared signal, said infrared signal transmission means being included in said portable unit housing, manual activation means included in said portable unit housing and operatively connected to said infrared signal transmission means for activating said infrared signal transmission means for transmitting an infrared signal, and directional delimiting means for directional delimiting said infrared signal transmitting from said infrared transmittal means to a predetermined angular region centered around a longitudinal axis of said portable unit in order that said infrared signal transmitted from said infrared signal transmission means be directed from said portable unit within said predetermined angular region so as to prevent that information units located outside said angular region detects said infrared signal emitted from said infrared signal transmission means.
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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) | 1999-07-23 | 2000-01-22 | 2000-07-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-23 | 2004-01-22 | 2004-07-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-23 | 2008-01-22 | 2008-07-23 | $7700.00 | Window Closed / Lapsed |