Pager subsystems
First Claim
1. In a low-power drain paging unit for receiving predetermined sequential tone-coded address signals followed by multitone FSK message signals and for printing out the message after decoding of the address signals which includes battery operated means for receiving said signals, for decoding a predetermined address and for actuating normally quiescent electrical apparatus of said pager in response thereto, said normally quiescent electrical apparatus being battery powered and including means for decoding the FSK message and means for displaying the decoded message, the improvement wherein said FSK message decoding means including means for producing a signal indicative of said FSK message by detecting only one of the tones of said FSK signal, whereby said one tone FSK decoding means contributes to reduce batter drain and extend the life of the pager.
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Accused Products
Abstract
A number of subsystems are disclosed for use in pagers in which the message transmitted, received and displayed is in alpha/numeric form. The subsystems include an encoder which displays the encoded message on an imprinted tape which is run continuously as an alarm when the memory of the encoder is overloaded. In a soft copy embodiment the encoder includes a keyboard and a dot matrix form of display both driven by a single logic circuit which cycles sequentially through all the alpha/numeric characters to provide simultaneously keyboard decoding and display activation. In another subsystem an end of message circuit is provided to sense the absence of transmitted characters by integration of the message signals, with a nonzero average indicating the end of the message. In a further subsystem, when FSK message signals are used, only one of the two tones is detected for message decoding. In a yet still further subsystem addressing of the pager is accomplished with a digital code and address decoding is accomplished with an improved bit recognition circuit utilizing a single comparator.
15 Citations
14 Claims
- 1. In a low-power drain paging unit for receiving predetermined sequential tone-coded address signals followed by multitone FSK message signals and for printing out the message after decoding of the address signals which includes battery operated means for receiving said signals, for decoding a predetermined address and for actuating normally quiescent electrical apparatus of said pager in response thereto, said normally quiescent electrical apparatus being battery powered and including means for decoding the FSK message and means for displaying the decoded message, the improvement wherein said FSK message decoding means including means for producing a signal indicative of said FSK message by detecting only one of the tones of said FSK signal, whereby said one tone FSK decoding means contributes to reduce batter drain and extend the life of the pager.
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6. In a paging unit including means for receiving predetermined address signals followed by a two-tone FSK message and for actuating the remainder of the pager circuitry to display the message to the recipient, the improvement in FSK decoding comprising:
Fsk message decoding means for producing a signal indicative of said FSK message by detecting only one of the two tones of the FSK signal. - View Dependent Claims (7, 8, 9, 10)
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11. In a paging unit including means for receiving predetermined address signals followed by message signals and for actuating the remainder of the pager circuitry to display the message to the recipient, the improvement comprising:
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means for decoding said message signal to produce a bilevel decoded message signal; and end-of-message decoding means including means for generating a deactivation signal responsive to the absence over a predetermined time period of signals in the decoded signal which represent one of the levels, when said absence exceeds said predetermined time period. - View Dependent Claims (12)
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- 13. A message encoder including a message entry keyboard, a memory for storing the message entered from the keyboard, display means for displaying the message in the memory, and means for reading out the memory to the display in a cyclic fashion to display all the contents of the memory over and over again in response to memory overload, to produce a highly visible indication of memory overload.
Specification