Passive infra-red proximity fuze

US4022132A · kind A · utility

Assignee

• AB Bofors

Inventors

• Ake Blomqvist · Karlskoga, SE
• Bertil Eriksson · Bissenkamp, SE

Key dates

• Filing date: Jun 17, 1975
• Grant date: May 10, 1977
• Expiry date: Jun 17, 1995

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F42C13/02
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Apparatus for use in a projectile-borne passive infra-red proximity fuse for detecting infra-red radiation emitted from a target. The apparatus includes at least one pair of optical means which are respectively located at spaced locations around the periphery of the projectile. The pair of optical means is so located that the beams of infra-red radiation associated therewith, which are both imaged upon a common detector, form an angle therebetween both in a plane through the longitudinal axis of the projectile and in a plane normal to such axis. Logic circuitry is provided and controlled by the detector to provide a distinctive output in response to the signals which are generated by the beams of radiation received from a target which is spinning about its longitudinal axis and is within a predetermined distance of the projectile. With the arrangement as described, the detection apparatus produces either two separate pulses or one long pulse for each revolution of the projectile about its longitudinal axis, whereas only a single pulse is produced for each revolution from distant sources of infra-red radiation such as the sun.