Intensity controlled infrared night vision imaging system for a vehicle

摘要

A night vision system 10 for a vehicle comprises a near infrared source 12 emitting a beam 22, a camera 16 receiving beam 24 once reflected by objects 26 to generate an image signal, and an image processor 18 generating a distribution of intensities, which may be a histogram 42, from the image signal, which it compares to a threshold to generate an image for display. The system 10 also includes an over-laid heads up display 20. Preferably the image processor 18 is arranged to reduce the intensities received by the camera 16 when the number of camera cells exceeding the intensity threshold is larger than a predetermined value, and increases intensities when the number of cells exceeding the threshold is smaller than a predetermined value. The system 10 may comprise an attenuator (102, fig. 4) or a variable power supply 14 to the source, to modify intensities received by the camera in response to the fore mentioned comparison. The source's 12 wavelength may be between 0.8žm to 0.9žm, and the system 10 is capable of viewing objects 26 within a range of 5m to 150m from the vehicle (21, fig. 1B). A method of viewing is also independently claimed.