What does a projector lamp consist of?
The lamp for a projector or projection TV consists of the bulb or lamp – it is a very powerful bulb, which is mounted in the lamp’s housing. The housing makes it easier to manipulate and replace the lamp in the projector or TV. Additionally, the housing ensures that the lamp is firmly and precisely fitted in the projector and that the bulb is connected to the power source. It also filters out the UV radiation produced by the light, protects the projector against a possible bulb explosion (thanks to the housing, glass shards cannot get into the projector’s optical systems) and has many other functions.
Lamp housing and its components
Lamp housing is pressed from temperature-resistant plastic, although some types are also partly made of metal. They contain the glass lens for filtering out UV radiation and directing the light flow. The housing includes the power cables, which are connected to the lamp on one side and to the connector on the other. While the lamp housing is plugged into the projector, the connector is securely connected to the lamp ballast (or driver) – a circuit that ensures the power supply, even though it is not part of the actual lamp housing.
The lamp housing usually includes screws to fasten the housing to the projector. Some lamp housing also contains a chip that measures the lamp’s illumination time.
Construction of projector bulbs
The most important part of the bulb is the burner, which is a clear glass tube containing a gaseous mixture with mercury. It also contains two tungsten electrodes, between which an electrical arc is formed once the bulb is switched on. This arc then reacts with the gaseous mixture to emit a light that is radiated equally in all directions. For this reason, a reflector is fitted around the burner – a glass flask of parabolic or elliptical shape with a reflective mirror coating inside. The reflector prevents light rays from shining in the wrong direction and also reflects the maximum amount of light produced forward into the projector’s optical system.
Some bulbs have a glass cover or lens for UV filtering located at the front of the reflector. However, sometimes this glass cover is part of the lamp housing or may even be a part of the projector’s actual lamp chamber. The bulb also usually contains two (sometimes three) connectors which connect to the electrodes in the burner and lead out from the back of the reflector.
Most projector lamps contain mercury-filled bulbs. There is a small amount of mercury in the burner of these bulbs. Mercury is harmful to our health, and even though the bulbs contain a very small amount (several milligrams) of mercury, we recommend that you handle these products carefully. If the bulb breaks or explodes in the projector, you should wear protective gloves when cleaning up the shards and ventilate the room thoroughly. Do not forget to dispose of old projector lamps in an ecological manner.
Who manufactures the bulbs for original lamps?
Currently, there are only a few manufacturers who make bulbs of sufficient quality for use in original lamp housing:
If you order an original lamp with housing, original bulb inside lamp or an original bare bulb without housing from our e-shop, it will always be equipped with a bulb from one of these manufacturers. These bulb brands have very similar characteristics and are mutually interchangeable. Even manufacturers of original lamps with housing occasionally use a lamp from another manufacturer if there is a shortage of bulbs on the market. If you insist on a bulb from a particular manufacturer when ordering an original bulb inside lamp or an original bare bulb, please state this in the notes section of your order.
For generic lamps with and without housing, you will receive a “no name” bulb which has similar parameters to the original product; however, it does not usually have the same projection quality or lifespan as an original bulb.