User presence detection systems for control of electronic devices

Inventors

Ghoshal, Sajol • Kramer, David • Martinez, Jaime

Assignees

Advanced Telesensors Inc

Abstract

An electronic device incorporating a liquid crystal display (LCD) screen comprises at least one at least one radio frequency (RF) antenna mounted behind a LCD panel of the LCD screen, and a processor. The RF antenna includes a directional transmit RF antenna that transmits an RF signal through the LCD panel to impinge on a human user, and includes a receive antenna configured to receive a RF signal reflected from tissue of the human user. The processor processes the reflected RF signal to generate a processed signal indicative of presence or absence of the human user, and responsive to the processed signal, controls an operating mode of the electronic device and/or enables control of the device by the human user.

Core Innovation

The invention provides an electronic device that includes a liquid crystal display (LCD) screen and at least one radio frequency (RF) antenna mounted behind a LCD panel. The at least one RF antenna includes a directional transmit RF antenna configured to transmit an RF signal forward through the LCD panel to impinge on tissue of a human user, and a receive antenna configured to receive a reflected RF signal that comprises a reflection of the RF signal impinged on the tissue of the human user.

At least one processor processes the reflected RF signal to generate a processed signal indicative of presence or absence of the human user. Responsive to the processed signal, the electronic device controls an operating mode of the electronic device or enables control by the human user of the electronic device. The processing comprises detection of gross motion, detection of respiration rate, and/or detection of a cardiac signal as an indicator of presence.

In some implementations, the processing dynamically adjusts sensitivity in the reflected RF signal processing to account for attenuation of the reflected RF signal attributable to transmission losses through the LCD panel and path loss to the human user. The operating mode control includes initiating a low power consumption mode or shutdown responsive to the processed signal indicating absence, and initiating a normal power consumption mode or activation responsive to the processed signal indicating presence.

Optionally, the processing includes identifying a cardiac signal signature of the human user and comparing the identified signature to at least one previously stored cardiac signal signature to authenticate the human user to generate the processed signal indicative of presence or absence. In another implementation, the processing comprises detection of respiration rate, blood pressure, and/or a cardiac signal, without identification of gross motion of the human user, as an indicator of presence of the human user.

Claims Coverage

The document includes two independent claims. Both cover an electronic device architecture with an LCD and RF antennas behind the LCD panel that generate a presence/absence processed signal from reflected RF signals and then use that signal to control operating mode or enable user control. The claims further define four inventive features.

Across the independent claims, the core claimed coverage centers on using an RF transmit/receive arrangement mounted behind an LCD panel to generate a processed presence/absence indication from reflected RF signals, then using that processed signal to control an operating mode or enable user control. The claims further refine the detection basis and include dynamic sensitivity adjustment for attenuation due to the LCD panel and path loss, plus optional authentication using stored cardiac signal signatures.

Stated Advantages

Documented Applications