Passive infrared sensor motion detection systems

A motion detection system, comprising:

• a first motion detection sensor comprising a first passive infrared sensor (first PIR) and a first optical system for focusing infrared radiation onto the first PIR, wherein the first optical system is configured to receive infrared radiation emanating from a first plurality of detection zones in an ambient of the first motion detection sensor;
• a second motion detection sensor comprising a second passive infrared sensor (second PIR) and a second optical system for focusing infrared radiation onto the second PIR, wherein the second optical system is configured to receive infrared radiation emanating from a second plurality of detection zones in an ambient of the second motion detection sensor, wherein one of the first and second motion detection sensors is vertically disposed above the other of the first and second motion detection sensors, and wherein each of the first and second optical systems have a horizontal field of view embodying:
• a first preset area extending from a central axis of their optical system to a same first preset angle relative to the central axis, wherein the first plurality of detection zones comprises a higher density of detection zones in its respective first preset area than the second plurality of detection zones comprises in its respective first preset area;
• and
• a second preset area extending from the same first preset angle to a same second preset angle relative to their central axis, wherein the second plurality of detection zones comprises a higher density of detection zones in its respective second preset area than the first plurality of detection zones comprises in its respective second preset area;
• and
• detection circuitry independently and operatively coupled to the first PIR and the second PIR, wherein the detection circuitry is configured to produce a motion detection signal upon receipt of a threshold signal from either the first PIR or the second PIR that indicates a predetermined change of infrared radiation has been detected at the respective PIR.

An apparatus, comprising:

• a germicidal source, wherein the apparatus is configured such that a germicide emitted from the germicidal source is projected exterior to the apparatus;
• and
• a motion detection system comprising:
• a first motion detection sensor comprising a first passive infrared sensor (first PIR) and a first optical system for focusing infrared radiation onto the first PIR;
• a second motion detection sensor comprising a second passive infrared sensor (second PIR) and a second optical system for focusing infrared radiation onto the second PIR, wherein the first and second motion detection sensors comprise different maximum detection distances;
• and
• detection circuitry independently and operatively coupled to the first PIR and the second PIR, wherein the detection circuitry is configured to send a motion detection signal to operational circuitry of the germicidal source upon receipt of a threshold signal from either the first PIR or the second PIR that indicates a predetermined change of infrared radiation has been detected at the respective PIR, and wherein the operational circuitry is configured to affect operation of the germicidal source subsequent to receipt of the motion detection signal.