Patent ID: 7170060

Claim:
A passive infrared sensor comprising: an infrared sensing element; a pair of optical components that set mutually substantially 180° opposing detection areas of the infrared sensing element; and a first main mirror and a second main mirror that cause infrared light from the detection areas to enter the infrared sensing element, wherein at least one first submirror with an orientation different from the orientation of the first main mirror is disposed on the first main mirror, with the first submirror being configured so that, in regard to the horizontal direction at the installation time of the passive infrared sensor, the orientation the first submirror is changed by a first predetermined angle, with respect to the orientation of the first main mirror, in a direction away from an attachment surface at the installation time, and in regard to the vertical direction at the installation time of the passive infrared sensor, the orientation the first submirror is changed by a second predetermined angle, with respect to the orientation of the first main mirror, in a direction downward at the installation time, and at least one second submirror with an orientation different from the orientation of the second main mirror is disposed on the second main mirror, with the second submirror being configured so that, in regard to the horizontal direction at the installation time of the passive infrared sensor, the orientation the second submirror is changed by a first predetermined angle, with respect to the orientation of the second main mirror, in a direction away from the attachment surface at the installation time, and in regard to the vertical direction at the installation time of the passive infrared sensor, the orientation the second submirror is changed by a second predetermined angle, with respect to the orientation of the second main mirror, in a direction downward at the installation time.