Motorola Corporation

Acoustic Technologies, Inc.

Ixys Corporation

Acoustic Technology, Inc.

Steven M Domer

Justin Lamar Allen

Kellie Michele Vanda

Samuel L Thomasson

Franklyn H Story

Roger L Hollstein

Frederic B Shapiro

Jeffery E Bills

Robert C Cichomski

LED junction temperature is determined in real time using the LED itself as the temperature sensor for directly measuring the LED junction temperature. In addition, temperature measurements from a silicon diode placed in proximity to the LED are also used to complement the temperature measurements from the LED itself. Arbitration is performed among temperature measurements from the LED and temperature measurements from the silicon diode to determine a temperature of the LED junction. The determined LED junction temperature may be used to make adjustments to the LED drive current. Temperature measurements from the LED are made in real time during actual operation by applying snooping currents to the LED during off-times of the PWM cycles of the LED, without interrupting normal operation of the LED.

In-situ LED junction temperature monitoring using LED as temperature sensor

Voice activity is detected by comparing a signal with two thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal.

Voice activity detector for telephone

Sub-band filtering, adaptive echo cancellation, and residual echo suppression are selectively and separately applied in hierarchical order under the control of a circuit that monitors four separate signals to determine n machine states. The number of machine states is further divided among m levels of noise in determining which, and how much of, sub-band filtering, adaptive echo cancellation, and residual echo suppression to use at any given time. A voice activity detector (VAD) is used to monitor each signal and provides statistical information in addition to whether or not a voice signal is detected. Sub-band filter, echo cancelling, and non-linear processing are not permitted to provide maximum reduction simultaneously. Even so, the invention provides at least 15 dB more echo suppression than systems without a sub-band filter bank series coupled with a non-linear processor in each channel.

Full duplex echo cancelling circuit

Voice activity is detected by comparing an analog signal with two voltage thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal. The input signal itself is not converted into digital form yet the data derived from the input signal has high resolution.

Analog voice activity detector for telephone

Voice activity is detected by comparing a signal with two thresholds and producing data representing the energy of the signal. The data, in binary form, is compared with thresholds to determine voice activity. In accordance with another aspect of the invention, the thresholds are adjusted based upon statistical information. In accordance with another aspect of the invention, the data can be weighted to provide an indication of the quasi-RMS energy of an input signal. In accordance with another aspect of the invention, voice activity detectors, individually weighted, are provided at each input and each output of a telephone for reliably controlling echo cancelling circuitry within the telephone.

Telephone having four VAD circuits

An imaging system ( ) and method compensate for different amplitudes of pixel signals generated by photoactive devices in an optical sensor ( ) whose responses to projected light are not uniform. The sensor is divided into regions ( ) such that the response of the photoactive devices within a region are substantially equal. A processing circuit ( ) compensates for different responses among different regions with a programmable gain amplifier ( ) whose gain is dynamically adjusted when pixel signals generated in different regions are received.

Imaging circuit and method of spatial compensation

A circuit and method color balance pixel signals (V ) on-the-fly in an image capturing system ( ). The pixel signals are amplified in a programmable gain amplifier ( ) whose gain is set by the ratio of a programmable capacitor ( ) to a fixed capacitor ( ). Control data (CONTROL) sets the capacitance of the programmable capacitor by enabling switches ( ) that enable binary weighted capacitors ( ). The control data adjusts the gain of the programmable amplifier as each pixel signal is applied, so that the pixel signals of all primary colors are amplified in the same programmable gain amplifier.

Color balancing circuit and method

A circuit for detecting when a fault condition has occurred includes an input stage responsive to a logic signal supplied to an input of the circuit for providing an output logic signal at an output thereof. An output stage, including a pulldown circuit, responsive to the output logic signal of the input stage, for providing an output logic signal at an output of the circuit. A fault detection circuit coupled to the output of the input stage and to the output stage for forcing the output of the circuit to a predetermined logic state when the pulldown circuit of the output stage is defective.

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Mesa, AZ, United States of America

Steven M Domer