|Figure 1. BMW displays the monitor on the center console to show Night Vision image. (Courtesy of BMW AG.)|
|Figure 2. The Night Vision camera on this Cadillac Deville is located in the center of the grille.|
Night vision enhancement systems are capable of detecting objects beyond the reach of normal headlamps and help with other unfavorable conditions like blinding headlamp glare from oncoming vehicles. They are not intended to be stared at by the driver, but rather serve as a supplemental aid for periodic glancing and peripheral view.
Night vision enhancement systems detect infrared (IR) light waves not visible to the human eye. They work by either detecting near infrared (NIR) light waves or far infrared (FIR) light waves. Both types use special cameras that are able to collect small amounts of infrared light and amplify it so it can be seen with human eyes. Knowing which type of night vision enhancement system a vehicle uses is important for identifying parts or when troubleshooting.
Near infrared (NIR) light waves are closest to the visible portion of the electromagnetic wave spectrum, but are not visible to the human eye. This is the same type of light emitted from remote controls that operate household electronics. Night vision enhancement systems that use NIR technology require IR "floodlamps" to project invisible NIR light onto the surrounding area. The camera captures the reflected NIR light from the surrounding area and intensifies it to create an enhanced (brightened) image of the normally dark area.
Far infrared (FIR) light waves are further away from the visible portion of the spectrum and are created by the heat emitted from objects. This type of technology may also be referred to as thermal imaging. It is ideal for detecting living things like people and animals. Because FIR light waves are created from emitted heat rather than reflections of light, night vision enhancement systems that use FIR technology do not require IR floodlamps to function.
Some vehicle models offer night vision enhancement as an optional accessory. General Motors was one of the first to offer a night vision enhancement system with the Night Vision on the 2000 Cadillac Deville, but discontinued its use after the 2005 model year because of decreasing sales. General Motor's Night Vision system used thermal infrared, or FIR, technology and used the head-up display (HUD) for displaying the Night Vision image.
BMW offers a similar type of system on some vehicle models, also called Night Vision, which uses the same type of FIR technology. The image is displayed on a monitor located on the center of the instrument panel (see Figure 1). BMW vehicles equipped with this system may also be equipped with an automatic high-beam dimming system called High-Beam Assist. These systems also help with nighttime driving by automatically switching from high to low beams when oncoming vehicles are detected.
Lexus began offering a night vision enhancement system on the 2003 LX470, called Night View. This system uses image enhancement or NIR technology and uses two IR floodlamps to light the road ahead with NIR light. The enhanced Night View image is displayed on the windshield using a HUD. 2007 Mercedes-Benz S-Class vehicles offer a similar type of system called Night View Assist, using the same NIR technology. On these vehicles the image is displayed on a high-resolution monitor located in the instrument cluster.
Both types of systems are likely to have parts located in areas vulnerable to collision damage. Certain steps should be followed to ensure that these systems work properly after repairs. There may be some safety concerns as well.
IR floodlamp service
Vehicles that use NIR systems are likely to have IR floodlamps located near the headlamps. On 2003-2006 Lexus LX470 models equipped with the Night View system, two IR floodlamps are located on the front bumper, below the headlamps. These are normal halogen bulbs, equivalent to ordinary high-beam headlamps, but use filters to prevent visible light rays from passing through. Only invisible NIR rays are emitted from the IR floodlamps. They only operate when the system is on and the vehicle is being driven over 6 km/h (4 mph). A beam indicator lamp, located above the Night View switch, will come on if the IR floodlamps are on.
An Inspection Mode can be used to check the IR floodlamps when the vehicle is stopped. However, caution should be used when working around these lights. This is because the IR light being emitted is invisible to the human eye, but equals the intensity of high-beam headlamps. Lexus recommends that the IR floodlamps not be looked at directly for more than five minutes. Serious eye injury can result from staring at these lamps at close range for a long period of time.
There are no specific aiming procedures for IR floodlamps, but deformed bumpers should be repaired or replaced to ensure that they are pointed in the proper direction. Check the Night View system for proper operation following all bumper repairs. This can be done with a night test drive or, as previously mentioned, by using the Inspection Mode if the vehicle is equipped.
Vehicles that use FIR, or thermal imaging, systems do not use IR floodlamps, but are likely to have the camera located on the front of the vehicle. These may require replacement if the vehicle is involved in a front end collision. The Night Vision camera used on the 2000-2005 Cadillac Deville is located in the center of the grille (see Figure 2). Depending on the design of the camera, it may have a serviceable, protective window.
The first design used on the 2000 Cadillac Deville is not serviceable, and must be sent to an authorized repair center for repair. Second design cameras can be identified by an electrical connection that attaches to the bottom side of the window. When replacing the protective window on second design cameras, it is important that they are installed properly. The protective window has a mirrored side and a black side. The black side has a scratch-resistant coating and should be installed facing outward.
Cameras used on NIR systems are typically located inside the passenger compartment, near the windshield. These are not as susceptible to damage as those located on the front of the vehicle. However, both types of cameras typically require specific steps for proper aiming if the camera is out-of-position or has been removed for replacement or during repairs. Refer to vehicle-specific service information for aiming cameras.
Before assuming that a system is not functional, ensure that it has been given time to warm up properly and the lens is clean. Outside cameras used on FIR systems may require extra time for the camera to heat up in cold climates. Cameras located inside the passenger compartment may also require time for the interior to be adequately warmed for the system to operate properly. Adverse weather conditions such as rain, snow, and fog will also affect the performance of these systems. With the exception of damage to replaceable protective windows, damaged or non-functional cameras will likely require replacement.
Night vision enhancement systems use IR technology to aid drivers during nighttime driving. They work by detecting either NIR or FIR light waves, invisible to the human eye, and displaying a brightened image of the dark road ahead. Knowing which type of system a vehicle is equipped with, and how it works, helps technicians to determine if it is functioning properly and how it should be repaired.