摘要 |
An image of a scene is focused onto a two dimensional array of passive infrared sensing elements mounted on and connected to an integrated circuit, and used to detect the location of events within the scene; for example, movement, change in temperature, or the emission of a gas. In this invention knowledge of the location of the event is derived from the detection of signals from one or more elements of the array, and is used to control the operation of a mechanism such that a portion of the scene including the event location is imaged onto a video imaging device operating in the visible or near infrared. Such mechanisms include a zoom lens or mirror arrangement and mechanical scanning in elevation and/or azimuth. Examples of suitable imaging devices for use with the thermal detector array include CCD camera chips and other electrically scanned silicon photovoltaic arrays. The CCD array might for example be used in a CCD camera, which is used to identify an intruder, or to read the number plate of a car. The event located within the scene may in addition be illuminated with a visible or infrared beam or a searchlight switched on and/or directed by the identification of an event by the thermal array.
|