US 5359647

Here is a concise summary of US patent 5359647:

US Patent 5359647: Headset in-use indicator

• Title: Headset in-use indicator
• Assignee: Plantronics Inc.
• Inventors: Paul L. Regen, Anna Marie G. Puentes, Richard Hensolt
• Filing Date: 1993-05-28
• Issue Date: 1994-10-25
• Abstract: A headset telephone is disclosed with an in-use indicator to notify passers-by when the wearer is engaged in a telephone conversation. In one embodiment, a light-emitting diode (LED) indicator is located on the headset's voice boom and illuminates when the headset is active. In another embodiment, headset activation triggers a transmitter to send a signal to a remote in-use indicator that is not physically connected to the telephone system or headset.

Plain-Language Overview of Independent Claims:

• Claim 1 (Independent): This claim describes a telephone headset in-use indicator system. It includes a headset with a microphone and receiver connected to a telephone base unit. The system has a circuit that amplifies the incoming audio signal (received audio signal lines), and an audio level detector that converts signal peaks exceeding a first threshold into current pulses. An integrator circuit then averages these current pulses into an "integration signal." A comparator evaluates this integration signal against a second threshold; if exceeded, it issues an "activation signal." This activation signal controls a switch, which, when closed, applies a DC voltage from a battery to the received audio signal line. Finally, an LED flasher circuit, connected to the received audio signal lines, uses this DC battery voltage to create a visual indication (e.g., flashing LED) that the headset is in use.
• Claim 4 (Independent): This claim describes a telephone headset in-use indicator system similar to Claim 1, but with a broader "visual indicator" instead of specifically an "LED flasher circuit" and an "amplifier circuit" instead of "transformer and amplifier circuit." It includes a headset with a microphone and receiver connected to a telephone base unit, an amplifier circuit to produce an amplified received audio signal, and an audio level detector that produces current pulses when the amplified signal exceeds a first threshold. An integrator circuit averages these pulses into an integration signal. A comparator generates an activation signal when the integration signal exceeds a second threshold. This activation signal controls a switch, which applies a DC voltage from a battery to the first received audio signal line. A visual indicator then uses this DC battery voltage to provide a visual indication of headset use.

CAFC 2026 Docket Search:
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