Passive infrared sensor systems and methods
AssigneeThe Texas A&M University System
InventorsYa Wang, Libo Wu, Zhangjie Chen
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Abstract
A passive infrared (PIR) sensor system, includes a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation, an electronic shutter positionable in a field of view (FOV) of the PIR sensor, wherein the electronic shutter includes a liquid crystal (LC) material, wherein the electronic shutter includes a first state providing a first transmissivity of IR radiation through the electronic shutter and a second state providing a second transmissivity of IR radiation through the electronic shutter that is less than the first transmissivity, and a shutter actuator configured to apply an actuation signal to the electronic shutter to actuate the electronic shutter between the first state and the second state.
Claims19
A passive infrared (PIR) sensor system, comprising:
- a PIR sensor configured to produce an out signal in res se to receiving infrared (IR) radiation;
- an electronic shutter positionable in a field of view (FOV) of the PIR sensor wherein the electronic shutter comprises a liquid crystal (LC) material wherein the electronic shutter comprises a first state providing a first transmissivity of IR radiation through the electronic shutter and a second state providing a second transmissivity of IR radiation through the electronic shutter that is les than the first transmissivity, and
- a shutter actuator configured to apply an actuation signal to the electronic shutter to actuate the electronic shutter between the first state and the second state, and wherein the actuation signal comprises a single pulse-width modulated (PWM) signal.
A passive infrared (PIR) sensor system, comprising:
- a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation;
- an electronic shutter positionable in a field of view (FOV) of the PIR sensor, wherein the electronic shutter comprises a liquid crystal (LC) material wherein the electronic shutter comprises a first state providing a first transmissivity of IR radiation through the electronic shutter and a second state providing a second transmissivity of IR radiation through the electronic shutter that is less than the first transmissivity;
- and
- a shutter actuator configured to apply an actuation signal to the electronic shutter to actuate the electronic shutter between the first state and the second state;
- wherein the electronic shutter comprises a LC element positioned between a pair of substrates.
A passive infrared (PIR) sensor system, comprising:
- a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation;
- a mechanical shutter positionable in a field of view (FOV) of the PIR sensor;
- and
- a shutter actuator configured to displace the mechanical shutter across an IR sensing element of the PIR sensor to at least partially block the IR radiation received by the PIR sensor in response to receiving a single pulse-width modulated (PWM) signal.
A passive infrared (PIR) sensor system, comprising:
- a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation;
- and
- a shutter assembly comprising a mechanical shutter positionable in a field of view (FOV) of the PIR sensor, wherein the shutter assembly comprises a shape memory alloy (SMA) element configured to displace the mechanical shutter across an IR sensing element of the PIR sensor to at least partially block the IR radiation received by the PIR sensor in response to receiving an actuator signal.
Dependencies are inferred from the claim text.