Passive infrared detector

• US 6,150,658 A
• Filed: 10/19/1998
• Issued: 11/21/2000
• Est. Priority Date: 10/20/1997
• Status: Expired due to Term

• Current Assignee: Atsumi Electric Co., Ltd.
• Original Assignee: Atsumi Electric Co., Ltd.
• Inventors: Hagiwara, Hiroshi
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Gabor, Otilia
• Application Number:
  US09/174,552
• Time in Patent Office: 764 Days
• Field of Search: 250/338.1, 250/DIG. 1, 250/349, 250/342, 250/353
• US Class Current: 250/338.1
• CPC Class Codes: G01J 5/0022 for sensing the radiation of moving bodies
• CPC Class Codes: G01J 5/0025 Living bodies ear thermometers G01J5/0011; detecting, measuring or recording for diagnostic purposes A61B5/00
• CPC Class Codes: G01J 5/04 Casings
• CPC Class Codes: G01J 5/047 Mobile mounting; Scanning arrangements
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0808 Convex mirrors
• CPC Class Codes: G01J 5/0814 Particular reflectors, e.g. faceted or dichroic mirrors
• CPC Class Codes: G01J 5/0831 Masks; Aperture plates; Spatial light modulators
• CPC Class Codes: G01J 5/084 Adjustable or slidable
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00
• CPC Class Codes: G08B 13/19 using infrared-radiation detection systems G08B13/194 takes precedence
• CPC Class Codes: Y10S 250/01 Passive intrusion detectors

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.

Claims

1. 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.

2. A passive infrared detector according to claim 1, wherein an indicating projection is provided on an outer periphery of said rotating plate, and a ceiling height is indicated on said sensor mounting plate opposite to said indicating projection.

3. A passive infrared detector according to claim 1, further comprising a radial slit communicated with said circumferential slit and extending straight in a radial direction of said rotating plate to enable the vertical angle of each sensor unit to be adjusted individually.

4. A passive infrared detector according to claim 3, wherein a monitoring distance setting character is indicated on a side of said radial slit.