Abstract: An infrared motion sensor system has an infrared (IR) sensor having a predetermined field of view, a target positioned within the field of view of the sensor which emits a spatially or temporally non-uniform pattern of IR radiation, and a processor which receives an output signal from the IR sensor, compares the received output signal to a signature temperature profile signal corresponding to the non-uniform pattern of IR radiation emitted by the target, and detects deviation of the sensor output signal from the signature temperature profile signal, indicating intervention of an object in a monitored volume between the target and sensor. The size of the target may be of the order of human size.

Abstract: An infrared motion sensor has a multi element IR detector with first and second separate arrays of optical elements associated with respective first and second detector elements and a partition of a material substantially opaque to IR radiation and substantially transparent to visible/NIR light arranged to separate the IR optical paths from the first and second optical elements to the respective first and second detector elements. In this way, the detector elements function individually with respect to IR radiation and individual optical elements produce separate and independently oriented fields of view on the first and second sides of the sensor, while visible/NIR light still falls on both detector elements so that detector element signals resulting from NIR radiation roughly cancel one another.

Abstract: A passive infrared sensor has two or more detector element arrays, each consisting of positive polarity and negative polarity elements. The signals from the arrays are both summed together and subtracted from each other, and if either the sum or difference signal exceeds a threshold, detection is indicated.

Abstract: A passive infrared sensor has two detection members established by respective detectors and optical elements, with alternating spatial volumes being monitored by each detection member. No dead space need exist between volumes. The detection members are configured such that a moving object causes the members to output different frequencies, whereas a non-moving stimulus produces the same frequency from both detection members.

Abstract: A passive infrared sensor has two or more detector element arrays, each consisting of positive polarity and negative polarity elements. The signals from the arrays are both summed together and subtracted from each other, and if either the sum or difference signal exceeds a threshold, detection is indicated.

Abstract: A piezoelectric detector circuit has at least one input line, a piezoelectric transducer in the input line, an amplifier receiving signals on the input line and generating an output, and one or two feedback elements through which the output is sent back to the input line. The circuit may be a discrete time sampled operational amplifier (DTOA) based transconductance or “voltage output mode” circuit. In one embodiment, protection elements are associated with amplifier input lines to establish a reference voltage.

Abstract: A passive infrared sensor has two or more element arrays, each consisting of positive polarity and negative polarity elements. The signals from the arrays are both summed together and subtracted from each other, and if either the sum or difference signal exceeds a threshold, detection is indicated.

Abstract: A temperature detection system for detecting relative or absolute temperatures of objects in a monitored area has at least one infrared (IR) detector and at least one optical element for directing IR radiation within a detector field of view onto the infrared detector. A scanning system is configured to produce relative movement between the optical element and the IR detector such that the detector field of view is scanned across a monitored area to receive IR radiation from objects in the monitored area. A signal processing module for receiving the detector output signal is configured to produce an output profile of the relative temperatures of objects in the monitored area. The IR detector may be a pyroelectric detector.

Abstract: A passive infrared sensor uses two detectors having elements of different configurations such that each element outputs a respective frequency when an object moves in front of it. Based on the presence of two frequencies with similar peak and/or slope characteristics, a motion signal is output to, e.g., activate an alarm. In another embodiment the detectors have plural elements with the elements of one detector being wired in a dimension that is orthogonal to the dimension in which the elements of the other detector are wired. The signals from the detectors are combined to determine motion and size of object. The detector elements can also be configured differently from each other as in the first embodiment, and the polarities of signals can be used to determine direction of motion. In yet another embodiment the detectors can be of the same size but have optics of different focal lengths.

Abstract: A passive infrared sensor uses two detectors having elements of different configurations such that each element outputs a respective frequency when an object moves in front of it. Based on the presence of two frequencies with similar peak and/or slope characteristics, a motion signal is output to, e.g., activate an alarm. In another embodiment the detectors have plural elements with the elements of one detector being wired in a dimension that is orthogonal to the dimension in which the elements of the other detector are wired. The signals from the detectors are combined to determine motion and size of object. The detector elements can also be configured differently from each other as in the first embodiment, and the polarities of signals can be used to determine direction of motion.

Abstract: A transconductance monitoring and amplifying circuit for a piezoelectric transducer that may be used in, e.g., a motion detector system includes a FET, with the transducer (and, hence, the signal voltage reference) floating between the gate and source of the FET, as opposed to being connected to the common ground of the circuit. This permits the development of a larger detector signal and concomitantly the use of a relatively inexpensive FET instead of a relatively more expensive high impedance operational amplifier as must be used in conventional transconductance circuits. The FET and transducer can be held in a single four-pin package. A discrete time sampled operational amplifier may also be used.

Abstract: A piezoelectric detector circuit has at least one input line, a piezoelectric transducer in the input line, an amplifier receiving signals on the input line and generating an output, and one or two feedback elements through which the output is sent back to the input line. The circuit may be a discrete time sampled operational amplifier (DTOA) based transconductance or “voltage output mode” circuit. In one embodiment, protection elements are associated with amplifier input lines to establish a reference voltage.

Abstract: A passive infrared sensor has two detector elements, each of which has a positive part and a negative part, with each detector element generating respective first and second signals. The signals are added together to render a “sum” signal and are also subtracted one from the other to render a “difference” signal, and a moving object is indicated only when the “sum” signal has a frequency different than the frequency of the “difference” signal.

Abstract: A transconductance monitoring and amplifying circuit for a piezoelectric transducer that may be used in, e.g., a motion detector system includes a FET, with the transducer (and, hence, the signal voltage reference) floating between the gate and source of the FET, as opposed to being connected to the common ground of the circuit. This permits the development of a larger detector signal and concomitantly the use of a relatively inexpensive FET instead of a relatively more expensive high impedance operational amplifier as must be used in conventional transconductance circuits. The FET and transducer can be held in a single four-pin package.

Abstract: A transconductance monitoring and amplifying circuit for a piezoelectric transducer that may be used in, e.g., a motion detector system includes a FET, with the transducer (and, hence, the signal voltage reference) floating between the gate and source of the FET, as opposed to being connected to the common ground of the circuit. This permits the development of a larger detector signal and concomitantly the use of a relatively inexpensive FET instead of a relatively more expensive high impedance operational amplifier as must be used in conventional transconductance circuits.