Automatic pager calling device

Claim 1

An automatic pager calling device, comprising; a ringing signal sensing means for sensing a ringing signal from public telephone lines; an audio frequency signal detecting means for detecting a dial tone, busy tone, click tone, and acceptance tone from the public telephone lines; a DTMF signal generating means for generating a first DTMF signal including a subscriber's pager subscription number and transmitting said first DTMF signal to the public telephone lines; a DTMF signal receiving means for receiving and reading a second DTMF signal from said public telephone lines and generating a subscription number received from a caller; an audio synthesizing means for generating a message indicating a subscriber is absent and a message requesting input of the subscription number of the caller, and transmitting said messages to the public telephone lines; a matching means for matching the public telephone lines with said DTMF signal generating means, said DTMF signal receiving means, said audio frequency signal detecting means, and said audio synthesizing means for enabling: (1) an output of said DTMF signal generating means and said audio synthesizing means to be transmitted to said public telephone lines without substantial attenuation or distortion, and (2) steady receipt of said DTMF signals and audio frequency signals from said public telephone lines by said DTMF signal receiving means and audio frequency signal detecting means; a switching means for selectively connecting and disconnecting said public telephone lines with said ringing signal sensing means and said matching means; a key inputting means for deriving the subscriber's pager subscription number; a memory for storing the subscriber's pager subscription number, the caller's identification code or subscription number, and a serial number and; a control means for storing in said memory the subscriber's pager subscription number derived by said key inputting means and controlling said audio frequency signal detecting means, said switching means, said audio synthesizing means, said matching means, said DTMF signal generating means, said DTMF signal receiving means and said memory, said control means controlling said switching means and said audio synthesizing means in response to a ringing signal being detected by said ringing signal sensing means so said public telephone lines are coupled to said matching means for enabling the subscriber's pager subscription number to be transmitted through said public telephone lines; said control means (a) receiving and storing in said memory the caller's subscription number and the serial number received by said DTMF signal receiving means; (b) activating said switching means to selectively couple and decouple said public telephone lines with said matching means; and (c) supplying the subscriber's pager subscription number and the received caller's subscription number and serial number stored in said memory to said DTMF signal generating means thereby to activate said DTMF signal generating means so it transmits said first DTMF signal indicative of the pager subscription number and the caller's subscription number and the serial number to said matching means in accordance with a signal indicative of the state of communication lines as derived from said audio frequency signal detecting means to call the subscriber's pager and send the caller's subscription number.