How do projector light bulbs work?

Projector headlights consist of a headlight assembly with a replaceable bulb, just like reflector headlights. They also include a reflector component, but that's where the similarities end.

The overall design of projector headlights is based around the idea of focusing light with a specially-shaped reflector, then using a shutter to project it on the road with a beam pattern that is evenly-distributed and tightly-organized.

Every projector headlight includes these basic components:

Bulb: Every headlight needs a bulb, and projector headlights can use halogen, HID, and LED bulbsas the light source. The bulbs in projector headlights can be much brighter than the bulbs in reflector headlights.

Reflector: Like classic reflector headlights, projector headlights actually include a component called a reflector. The difference is that they use an elliptical-shaped reflector instead of a parabolic-shaped one. The difference in shape causes the light emitted from the bulb in a projector headlight to focus on a narrow point near the front of the reflector, where it meets a shutter.

Shutter: The shutter is one of the most important components in a projector headlight, and it's something that classic reflector headlight housings just don't have. This component is inserted into the light beam from below, which causes a sharp cutoff and effectively aims the light at the road instead of allowing it to blind other drivers. In some vehicles, the shutter can be raised and lowered to switch between high and low beams.

Lens: This is the final component found in projector headlights, and it's designed to evenly distribute the beam of light that has already been shaped and aimed by the elliptical reflector and the shutter. Some projector headlight lenses also have a feature that softens the cutoff line between light and dark when the headlights shine on the road.

Replacement Bulbs for Project Lights

The basic design of projector lights is generally the same, but different bulbs can be used in this system:

Halogen bulbs:Used in reflector headlights, halogen lights were also installed in the first projector headlights introduced to the market.

HID bulbs:These are also known as Xenon HID headlights and are still available. HID bulbs are brighter than halogens and have a longer lifespan.

LED bulbs:Highly energy-efficient, LEDs are the newest innovation. They have a longer lifespan than halogens or HIDs. Experts say that if these bulbs do not suffer any kind of damage, they could outlive even the lifespan of the vehicles they are fitted in.

Types of Projector Headlights: Halogen, HID, LED, Halo

All projector headlights are based on the same basic design, but they can use several different types of bulbs. These are the main types of projector headlights that you'll run into out on the road, including a brief explanation of what sets each one apart from the rest:

Halogen projector headlights: The first projector headlights used halogen bulbs, just like reflector headlights. These headlights typically project a more even beam of light than reflectors, with a sharper cutoff between light and dark, even though they use the older halogen bulb technology.

HID projector headlights: The second type of projector headlights to arrive used HID bulbs, and they are still available today. These are also known as Xenon HID headlights. They're much brighter than traditional halogen bulbs, and they also last longer. In most cases, it's a bad idea to put HID bulbs into projector housings designed for halogen, because they're so much brighter.

LED projector headlights: These are a more recent innovation. They're very energy efficient, and they last far longer than either halogen or HID headlights. If they're never damaged in any way, LED projector headlights can even outlive the operational lifespan of the vehicle they're installed in.

Halo or Angel Eye projector headlights: This refers to the distinctive ring, or halo, of light that you see in some projector headlights. Even though manufacturers sometimes refer to these as halo or angel eye projector headlights, the ring itself does not use projector technology. These rings are created with about a half dozen different technologies like cold cathode fluorescent lighting (CCFL) tubes, LEDs, and even incandescent bulbs.