Patent US4650928A successfully refreshed from Google Patents.
US4650928A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal transmitting and/or receiving apparatus
Assignee: Sony Corp
•
Filing: 1985-06-07
•
Granted: 1987-03-17
•
Expires: 2005-06-07
Abstract
Abstract A cordless telephone comprises a base unit and a plurality of remote units. The remote units are respectively adapted to establish radio communication at separate times with the base unit. Each remote unit generates a particular code in a particular format that includes at least one interval in which the particular code is present and at least one interval from which the particular code is absent. The particular code and particular format of each remote unit are different from those of the other remote units. A transmitter in each remote unit transmits the particular code of that unit in the particular format thereof to the base unit. The particular formats are such that the transmission of each particular code periodically corresponds to non-transmission of all of the other particular codes of the remote units. The particular codes can thus periodically be received by the base unit without interference caused by transmission of the other particular codes. The base unit echoes the particular code transmitted by a selected one of the remote units, and each of the remote units detects whether or not its own particular code matches the particular code echoed by the base unit. In response to such a match, a communication channel is established between the base unit and the one of the remote units in which the match occurs. The communication channel while established precludes establishment of a communication channel between the base unit and any of the other remote units.
Inventors
- 👤 Norio Numata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:15
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/38; H04M; H04M1/00; H04M1/72; H04M1/725; H04M1/727
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
272 words
Apparatus comprising a base unit and a plurality of remote units, said remote units being respectively adapted to establish radio communication at separate times with said base unit; each of said remote units comprising: means for generating a particular code in a particular format that includes at least one interval in which said particular code is present and at least one interval from which said particular code is absent, the particular code and particular format of each remote unit being different from those of the other remote units of said plurality of remote units, and means for transmitting said particular code in said particular format to said base unit; said particular formats being such that the transmission of each of said particular codes periodically corresponds to non-transmission of all of the other particular codes of said plurality of remote units, whereby each of said particular codes can be periodically received by said base unit without interference caused by transmission of the other particular codes of said plurality of remote units; said base unit comprising means for echoing the particular code transmitted by a selected one of said remote units; and each of said remote units further comprising means for detecting whether or not its own particular code matches said particular code echoed by said base unit; and further comprising means responsive to such a match for establishing a communication channel between said base unit and the one of said plurality of remote units in which such match occurs, said communication channel while established precluding establishment of a communication channel between said base unit and any other of said plurality of remote units.
Claim 2
Dependent Claim
272 words
Apparatus comprising a base unit and a plurality of remote units, said remote units being respectively adapted to establish radio communication at separate times with said base unit; each of said remote units comprising: means for generating a particular code in a particular format that includes at least one interval in which said particular code is present and at least one interval from which said particular code is absent, the particular code and particular format of each remote unit being different from those of the other remote units of said plurality of remote units, and means for transmitting said particular code in said particular format to said base unit; said particular formats being such that the transmission of each of said particular codes periodically corresponds to non-transmission of all of the other particular codes of said plurality of remote units, whereby each of said particular codes can be periodically received by said base unit without interference caused by transmission of the other particular codes of said plurality of remote units; said base unit comprising means for echoing the particular code transmitted by a selected one of said remote units; and each of said remote units further comprising means for detecting whether or not its own particular code matches said particular code echoed by said base unit; and further comprising means responsive to such a match for establishing a communication channel between said base unit and the one of said plurality of remote units in which such match occurs, said communication channel while established precluding establishment of a communication channel between said base unit and any other of said plurality of remote units.
Claim 3
Dependent Claim
15 words
Apparatus according to claim 1; wherein each of said remote units is a cordless telephone.
Claim 4
Dependent Claim
61 words
Apparatus according to claim 2; wherein each of said remote units comprises means for generating an up channel audio signal, frequency modulator means responsive to said up channel audio signal for generating a frequency modulated up channel signal, and antenna means response to said frequency modulated up channel signal for transmitting said frequency modulated up channel signal to said base unit.
Claim 5
Dependent Claim
71 words
Apparatus according to claim 3; wherein each of said remote units further comprises control means for generating a code signal including said particular code and minimum shift keying modulating means response to said code signal for generating a modulated audio frequency code signal, said frequency modulator means being responsive to said modulated audio frequency code signal, whereby said audio frequency code signal is frequency modulated for transmission to said base unit.
Claim 6
Dependent Claim
33 words
Apparatus according to claim 4; wherein each of said remote units further comprises keying switch means connected to said control means for keying in the number of a third person to be called.
Claim 7
Dependent Claim
35 words
Apparatus according to claim 4; wherein each of said remote units further comprises talk switch means connected to said control means for selectively placing said control units in a standby mode or a talk mode.
Claim 8
Dependent Claim
35 words
Apparatus according to claim 4; wherein each of said remote units further comprises channel switch means connected to said control means for selecting one of a plurality of channels for communication with said base unit.
Claim 9
Dependent Claim
39 words
Apparatus according to claim 4; wherein each of said remote units further comprises first dip switch means connected to said control means for generating an identifying code unique to the combination of said base unit and said remote units.
Claim 10
Dependent Claim
28 words
Apparatus according to claim 4; wherein said means in each said remote units for generating said particular code comprises second dip switch means connected to said control means.
Claim 11
Dependent Claim
59 words
Apparatus according to claim 4; wherein said base unit comprises means for generating a down channel audio signal, frequency modulator means responsive to said down channel audio signal for generating a frequency modulated down channel signal, and antenna means responsive to said frequency modulated down channel signal for transmitting said frequency modulated down channel signal to said base units.
Claim 12
Dependent Claim
98 words
Apparatus according to claim 10; wherein said base unit further comprises control means for generating a code signal selectively including the particular code of one of said remote units or a code common to all of said remote units and minimum shift keying modulating means responsive to said code signal for generating a modulated audio frequency code signal, said frequency modulator means in said base unit being responsive to said modulated audio frequency code signal in said base unit, whereby said audio frequency code signal in said base unit is frequency modulated for transmission to said remote units.
Claim 13
Dependent Claim
42 words
Apparatus according to claim 11; wherein said base unit further comprises channel switch means connected to said control means in said base unit for selectively placing said base unit in one of a plurality of channels for communication with said remote units.
Claim 14
Dependent Claim
41 words
Apparatus according to claim 11; wherein said base unit further comprises third dip switch means connected to said control means in said base unit for generating an identifying code unique to the combination of said base unit and said remote units.
References Cited (Backward Citations)
US4332981A
Cited
EP0069275A1
Cited
GB2108806A
Cited
EP0074940A1
Cited
GB2110055A
Cited
WO1983002380A1
Cited
GB2124454A
Cited
US4517561A
Cited
EP0106400A1
Cited
GB2144309A
Cited
US4574163A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-16 | 1990-09-15 | 1991-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-16 | 1994-09-15 | 1995-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-16 | 1998-09-15 | 1999-03-17 | $7700.00 | Window Closed / Lapsed |