Telephonic communications – Supervisory or control line signaling – Signal reception at substation
Reexamination Certificate
1999-04-30
2004-02-03
Harvey, Minsun Oh (Department: 2644)
Telephonic communications
Supervisory or control line signaling
Signal reception at substation
C379S418000
Reexamination Certificate
active
06687369
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for discriminating two or more telephone signals from a pair of telephone wires making the process invisible to the user, and more particularly, to a device that includes timing circuitry to mute out the call for a predetermined period of time until the coded call is identified and forwarded to the intended telephone set or sets with a unique number.
2. Description of the Related Art
The conventional telephone line utilizes one pair of wires carrying a D.C. voltage that is modulated when voice/sound is transmitted. The ring signal is an alternating signal superimposed on the D.C. voltage. Some telephone companies provide a service wherein the ring signal is coded and depending on the number of rings, one, two, three (or even more), distinctive sounds are generated. In this manner, a user can determine which of his two (or three or more) numbers is being called even though only one pair of wires is being used. The problem is that the user is required to make this determination and electronic devices, such as fax machines, are typically not equipped to do this. Also, visitors to the household, the elderly, or others with similar limitations, may find it difficult to determine which line is being called.
The present invention provides a simple reliable device to discriminate the incoming calls directing them to the intended set muting out the others. Thus, the result is that the discrimination process is invisible to a user and simulates the existence of additional independent lines.
SUMMARY OF THE INVENTION
It is one of the main objects of the present invention to provide a device that operates with one pair of telephone wires with coded ring signals to discriminate between two or more incoming calls and activates only predetermined telephone sets, faxes or other similar devices.
It is another object of this invention to provide a telephone signal discriminator that utilizes minimal electric power from the telephone network.
It is still another object of the present invention to provide a device that permits a user to operate a telephone line with a pair of wires as if more pairs of wires were present.
It is yet another object of this invention to provide such a device that is inexpensive to manufacture and maintain while retaining its effectiveness.
Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
REFERENCES:
patent: 4219700 (1980-08-01), Panizzon et al.
patent: 4536619 (1985-08-01), Hamatani et al.
patent: 4782518 (1988-11-01), Mattley et al.
patent: 5142569 (1992-08-01), Peters et al.
patent: 5327493 (1994-07-01), Richmond et al.
patent: 5537657 (1996-07-01), King, III
Harold Jefferey
Harvey Minsun Oh
Sanchelima J.
LandOfFree
Telephone signal discriminator does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Telephone signal discriminator, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Telephone signal discriminator will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3277196