Patent US5521975A successfully refreshed from Google Patents.
US5521975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telephone terminal device with means for detecting abandonment of call
Assignee: Hashimoto Corp
•
Filing: 1994-08-11
•
Granted: 1996-05-28
•
Expires: 2014-08-11
Abstract
Abstract A telephone terminal device, which is activated by a predetermined number of ringing signals even if a telephone call occurred immediately after a previous caller had abandoned a call before engagement of the telephone line. When the telephone terminal device is set to standby mode, the polarity of telephone line (L1, L2) is stored in microprocessor CPU-1 via photocoupler PC-3 (or PC-4) and contact y2-1. If there is a call thereafter, ringing portion of the ringing signal is detected by photocoupler PC-3 (or PC-4) via capacitor C2. During a silent period, the polarity of the telephone line (L1, L2) is checked by the aforementioned PC-3 or PC-4 via contact y2-1 which is closed. When the polarity of the telephone line at the time of abandonment of call by a caller prior to activation of the telephone terminal device coincides with the aforementioned polarity stored, the telephone terminal device is restored to standby mode (with the counter for ranging signals being cleared).
Inventors
- 👤 Kazuo Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:12
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/64; H04M1/65; H04M1/654
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
149 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a telephone terminal device with means for detecting abandonment of a call, said telephone terminal device comprising: storage means for storing a value indicating polarity of a telephone line prior to reception of a ringing signal on said telephone line; ringing signal detecting means for detecting ringing signals; means for activating said telephone terminal device when a predetermined number of said ringing signals are counted; means for comparing polarity stored in said storage means with polarity of said telephone line during silent portions of said ringing signals or polarity of said telephone line at time of abandonment of said ringing signals, said silent portions and said abandonment occurring prior to activation of said telephone terminal device; and means for restoring said telephone terminal device to standby condition when said compared polarities coincide.
Claim 2
Dependent Claim
149 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a telephone terminal device with means for detecting abandonment of a call, said telephone terminal device comprising: storage means for storing a value indicating polarity of a telephone line prior to reception of a ringing signal on said telephone line; ringing signal detecting means for detecting ringing signals; means for activating said telephone terminal device when a predetermined number of said ringing signals are counted; means for comparing polarity stored in said storage means with polarity of said telephone line during silent portions of said ringing signals or polarity of said telephone line at time of abandonment of said ringing signals, said silent portions and said abandonment occurring prior to activation of said telephone terminal device; and means for restoring said telephone terminal device to standby condition when said compared polarities coincide.
Claim 3
Dependent Claim
151 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a telephone terminal device with means for detecting abandonment of a call, said telephone terminal device comprising: storage means for storing a value indicating polarity of a telephone line prior to reception of a ringing signal on said telephone line; ringing signal detecting means for detecting ringing signals; means for activating said telephone terminal device when a predetermined number of said ringing signals are counted; means for comparing polarity stored in said storage means with polarity of the telephone line during silent portions of said ringing signals or polarity of the telephone line at the time of abandonment of said ringing signals, said silent portions and said abandonment occurring prior to activation of said telephone terminal device; and means capable of maintaining reception of said ringing signals when said compared polarities do not coincide.
Claim 4
Dependent Claim
151 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a telephone terminal device with means for detecting abandonment of a call, said telephone terminal device comprising: storage means for storing a value indicating polarity of a telephone line prior to reception of a ringing signal on said telephone line; ringing signal detecting means for detecting ringing signals; means for activating said telephone terminal device when a predetermined number of said ringing signals are counted; means for comparing polarity stored in said storage means with polarity of the telephone line during silent portions of said ringing signals or polarity of the telephone line at the time of abandonment of said ringing signals, said silent portions and said abandonment occurring prior to activation of said telephone terminal device; and means capable of maintaining reception of said ringing signals when said compared polarities do not coincide.
Claim 5
Dependent Claim
166 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, apparatus for receiving the ringing signals from the telephone line to activate a telephone terminal device, comprising: means for detecting a polarity of a voltage supplied by said telephone line before receiving said ringing signals, means for checking the polarity of the voltage supplied by said telephone line after receiving at least one of said ringing signals, means for counting said ringing signals to activate said telephone terminal device when a predetermined number of said ringing signals is received, and means responsive to the polarity detected by said detecting and checking means for controlling said counting means to continue counting said ringing signals when the polarity detected by said checking means does not coincide with the polarity detected by said detecting means, and for resetting said counting means to an initial state when the polarity detected by said checking means coincides with the polarity detected by said detecting means.
Claim 6
Dependent Claim
166 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, apparatus for receiving the ringing signals from the telephone line to activate a telephone terminal device, comprising: means for detecting a polarity of a voltage supplied by said telephone line before receiving said ringing signals, means for checking the polarity of the voltage supplied by said telephone line after receiving at least one of said ringing signals, means for counting said ringing signals to activate said telephone terminal device when a predetermined number of said ringing signals is received, and means responsive to the polarity detected by said detecting and checking means for controlling said counting means to continue counting said ringing signals when the polarity detected by said checking means does not coincide with the polarity detected by said detecting means, and for resetting said counting means to an initial state when the polarity detected by said checking means coincides with the polarity detected by said detecting means.
Claim 7
Dependent Claim
20 words
The apparatus of claim 3, wherein said checking means detect the polarity during a silent period of said ringing signals.
Claim 8
Dependent Claim
28 words
The apparatus of claim 3, wherein said counting means are reset when a first sequence of said ringing signals is terminated before said telephone terminal device is activated.
Claim 9
Dependent Claim
40 words
The apparatus of claim 5, wherein said telephone terminal device is activated by said counting means when the predetermined number of said ringing signals in a second sequence is received after the first sequence of the ringing signals are terminated.
Claim 10
Dependent Claim
170 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a method of receiving the ringing signals from the telephone line to activate a telephone terminal device comprising the steps of: detecting a polarity of a voltage supplied by said telephone line before receiving said ringing signals, checking the polarity of the voltage supplied by said telephone line after receiving at least one of said ringing signals, counting said ringing signals in a first sequence of the ringing signals to activate said telephone terminal device when a predetermined number of said ringing signals is received, said step of counting being carried out until the polarity detected after receiving at least one of said ringing signals coincides with the polarity detected before receiving said ringing signals, and thereafter, counting said ringing signals in a second sequence of the ringing signals to activate said telephone terminal device when the predetermined number of said ringing signals in the second sequence of the ringing signals is received.
Claim 11
Dependent Claim
170 words
In a telephone system wherein ringing signals cause a change in a polarity of a telephone line, a method of receiving the ringing signals from the telephone line to activate a telephone terminal device comprising the steps of: detecting a polarity of a voltage supplied by said telephone line before receiving said ringing signals, checking the polarity of the voltage supplied by said telephone line after receiving at least one of said ringing signals, counting said ringing signals in a first sequence of the ringing signals to activate said telephone terminal device when a predetermined number of said ringing signals is received, said step of counting being carried out until the polarity detected after receiving at least one of said ringing signals coincides with the polarity detected before receiving said ringing signals, and thereafter, counting said ringing signals in a second sequence of the ringing signals to activate said telephone terminal device when the predetermined number of said ringing signals in the second sequence of the ringing signals is received.
Claim 12
Dependent Claim
21 words
The method of claim 7, wherein said step of checking is carried out during a silent period of said ringing signals.
Claim 13
Dependent Claim
41 words
The method of claim 7, wherein said step of counting said ringing signals in the second sequence of the ringing signals is carried out when the first sequence of said ringing signals is terminated before said telephone terminal device is activated.
Claim 14
Dependent Claim
44 words
The method of claim 9, wherein said telephone terminal device is activated by the second sequence of said ringing signals when the predetermined number of said ringing signals in said second sequence is received after the first sequence of the ringing signals are terminated.
References Cited (Backward Citations)
US4079210A
Cited
GB2160390A
Cited
US4975940A
Cited
US4679229A
Cited
US5063589A
Cited
JPH01107913A
Cited
US4914690A
Cited
US5119418A
Cited
US5159626A
Cited
US5402482A
Cited
US5329584A
Cited
US5293420A
Cited
GB2271244A
Cited
US5406623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |