US 6,150,658 AGranted

Passive infrared detector

AssigneeAtsumi Electric Co., Ltd.

InventorHiroshi Hagiwara

Life of this patent

Estimating the term…

Loading patent…

Abstract

A passive infrared detector that enables the extent of the field to be 360 degrees in circumference with a simple arrangement and allows the field range in the vertical direction to be adjusted wholly or partially. A plurality of sensor units are circumferentially arranged on a sensor mounting plate. Each sensor unit has a reflecting mirror and a sensing element placed at the focus position of the mirror. Each sensor unit is rotatable in the vertical direction. A slot is formed radially in the sensor mounting plate opposite to each sensor unit. A rotating plate is rotatably mounted on the sensor mounting plate. A circumferential slit is formed circumferentially in the rotating plate such that the distance from the center of the rotating plate to the circumferential slit gradually decreases. An adjusting rod is connected at one end thereof to each sensor unit. The other end of the adjusting rod extends through the slot and the circumferential slit.

Claims4

Dependent claims

A passive infrared detector comprising:

a plurality of sensor units each including a reflecting mirror and a sensing element placed at a position of a focus of said reflecting mirror;
a sensor mounting plate having said sensor units arranged thereon in a circumferential direction, each sensor unit being rotatable in a vertical direction;
a slot formed radially in said sensor mounting plate opposite to each of said sensor units;
a rotating plate rotatably mounted on said sensor mounting plate;
a circumferential slit former circumferentially in said rotating plate such that a distance from a center of said rotating plate to said circumferential slit gradually decreases;
and
an adjusting rod connected at one end thereof to each sensor unit, the other end of said adjusting rod extending through said slot and said circumferential slit;
wherein movement of said circumferential slit caused by rotation of said rotating plate is transmitted to said adjusting rod to cause said adjusting rod to move in said slot, thereby enabling a vertical angle of each sensor unit to be adjusted.

5 more elements

Dependencies are inferred from the claim text.