US5329620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Daisy chainable voice-data terminal
Assignee: One Touch Systems Inc
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Filing: 1992-03-25
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Granted: 1994-07-12
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Expires: 2012-03-25
Abstract
Abstract A daisy chain voice-data terminal for communicating data and voice signals between remote locations, comprising, according to an embodiment of the present invention, a microcomputer with a RAM for main memory and an EPROM for program memory, a membrane keypad connected to an input port of the microcomputer, a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer, a microphone and preamplifier, a differential output audio amplifier, a relay controlled by the microcomputer to switch the differential output audio amplifier on and off a daisy chain cable connected to other response keypads and a site controller, an RS-485 serial input/output to interface the microcomputer to the daisy chain cable, a switching regulator to provide five volts to the logic circuits, and a separate three-terminal linear regulator to supply five volts to the audio circuits. At each response keypad, the wiring for the audio channel is cross connected to balance out any noise that may be otherwise induced in the audio signal.
Inventors
- 👤 Gary D. Alford
- 👤 Robert E. Sellers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:29
CPC Classifications
G; G09; G09B; G09B5/00; G09B5/08; G09B5/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
115 words
A response keypad unit, comprising: an electret microphone; an audio amplifier having an input connected to the microphone and having a differential output for low-noise operation; a daisy chain cable to distribute on a differential wire pair an audio channel, a digital serial input/output (SIO) channel and a power bus; switching means connected to the daisy chain cable and said differential output of the audio amplifier for selectively coupling the audio amplifier to the daisy chain; and microcomputer means connected to the daisy chain cable and including means for responding to a plurality of signals present on said SIO channel and including means for issuing a signal to the switching means to change its status.
Claim 2
Dependent Claim
115 words
A response keypad unit, comprising: an electret microphone; an audio amplifier having an input connected to the microphone and having a differential output for low-noise operation; a daisy chain cable to distribute on a differential wire pair an audio channel, a digital serial input/output (SIO) channel and a power bus; switching means connected to the daisy chain cable and said differential output of the audio amplifier for selectively coupling the audio amplifier to the daisy chain; and microcomputer means connected to the daisy chain cable and including means for responding to a plurality of signals present on said SIO channel and including means for issuing a signal to the switching means to change its status.
Claim 3
Dependent Claim
143 words
A response keypad, comprising a microcomputer with a RAM for main memory and an EPROM for program memory; a membrane keypad connected to an input port of the microcomputer; a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer; a microphone and associated preamplifier; a differential output audio amplifier for receiving an amplified audio signal from the microphone; a relay means controlled by the microcomputer for switching the differential output audio amplifier on and off an audio channel in a daisy chain cable connected to other response keypads and a site controller; a differential serial input/output for interfacing the microcomputer to said daisy chain cable; a switching regulator to provide a first regulated voltage to the microcomputer; and a three-terminal linear regulator for supplying operating power to the microphone, associated preamplifier and differential output audio amplifier.
Claim 4
Dependent Claim
143 words
A response keypad, comprising a microcomputer with a RAM for main memory and an EPROM for program memory; a membrane keypad connected to an input port of the microcomputer; a liquid crystal display adjacent to the keypad and connected to an output port of the microcomputer; a microphone and associated preamplifier; a differential output audio amplifier for receiving an amplified audio signal from the microphone; a relay means controlled by the microcomputer for switching the differential output audio amplifier on and off an audio channel in a daisy chain cable connected to other response keypads and a site controller; a differential serial input/output for interfacing the microcomputer to said daisy chain cable; a switching regulator to provide a first regulated voltage to the microcomputer; and a three-terminal linear regulator for supplying operating power to the microphone, associated preamplifier and differential output audio amplifier.
Claim 5
Dependent Claim
30 words
The response keypad of claim 2, wherein: wiring connections for said audio channel are cross connected to balance out digital noise that may be otherwise induced in the audio signal.
References Cited (Backward Citations)
US4903200A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-07-11 | 1998-01-10 | 1998-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-11 | 2002-01-10 | 2002-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-11 | 2006-01-10 | 2006-07-12 | $7700.00 | Window Closed / Lapsed |