A
AC
A type of metal halide lamp. An abbreviation for High pressure, mercury Arc lamp.
Air filter
Part in a projector designed to provide clean airflow inside the projector. If it becomes blocked in any way the projector can overheat inside and lead to early lamp failure. It is recommended to clean the air filter regularly in the projector. Some manufacturers provide new air filters with every new replacement lamp.
ANSI lumens
A standard for measuring light output, used for comparing projectors. ANSI lumens is a measuring method of the American National Standards Institute IT7.228. Unfortunately there are enough variables that the eye will often disagree with the ANSI rating. Such variables include:-
- Halogen lamp projectors against metal halide lamp projectors. The halogen version will seem noticeably dimmer even if the 2 units rate the same ANSI lumens.
- Type of LCD technology used (active matrix TFT or Polysilicon).
- Type of overall technology used (LCD vs DLP vs CRT)
- Contrast ratio
On balance, however, ANSI lumens still offer a good guide to image brightness.
B
Brightness
The attribute of visual perception in accordance with which an area appears to emit more of less light. (Luminance is the recommended name for the photo-electric quantity which has also been called brightness).
BriteOptic Dual Lamp system
This feature delivers the power of 2 high intensity lamps through a high pressure prism and leads to an improved light integrator system. Used exclusively on some Panasonic projectors, BriteOptic is a trademark of Matsushita Electric Industrial Co. Ltd.
C
Colour temperature
A method of measuring the "whiteness" of a light source. Metal halide lamps have very high temperatures compared to halogen and other incandescent lights.
Contrast ratio
The ratio between white and black. The larger the contrast ratio the greater the ability of a projector to show subtle colour details and bear extraneous room light. There are 2 methods used in the projection industry:-
- Full on/off contrast measures the ratio of the light output of an all white image (full on) and the light output of an all black image (full off)
- ANSI contrast is measured with a pattern of 16 alternating black and white rectangles. The average light output from the white rectangles is divided by the average light output of the black rectangles to work out the ANSI contrast ratio.
D
Dichroic
A mirror or lens that reflects or refracts selective wavelengths of light. Typically used in projector light engines to separate the lamps "white" light into red, green and blue light.
Dual lamp mode
Normal lamp mode delivers high brightness operation. Economy mode allows the projector to operate more economically providing longer lamp life. Please note brightness can be reduced by up to 20% in economy mode. Most projectors now carry this feature.
Dual lamp system
Some high end projectors are supplied with 2 lamps guaranteeing that your show or presentation can continue without interruption. Should 1 lamp fail the other lamp can be utilized.
F
FXL
A type of halogen lamp and the most popular lamp type used in halogen projectors. The lamp typically lasts 40-50 hours, however for convenience, most projectors with halogen lamps carry a spare to switch over once the first lamp has blown.
H
Halogen lamps
Used in low and medium priced projectors, these lamps last about 40-50 hours with consistent performance throughout their life. They give off a yellowish image compared to metal halide lamps which have a more true white image. In most cases, projectors with halogen lamps are fitted with a lamp changer to switch to a second lamp when necessary.
Hi Lo mode
Most new projectors have this feature allowing you to run the metal halide lamp more efficiently in Lo mode thereby increasing the lamp life.
L
Lamp assembly
A term to describe the lamp and its lamp housing. Also known as lamp ballast.
Lamp module
A term to describe the plastic casing that holds the lamp. Most lamps are supplied in this form to make replacing the lamp in your projector quick and easy. To replace a lamp module you simply undue the necessary screws on your projector, lift out the old lamp module, insert the new lamp module and tighten the screws. Specific instructions on how to replace the lamp module may vary from projector to projector so it is advisable to consult the instruction manual.
Lamp only
Some lamps are only available in their bare form. Also a few manufacturers do offer the choice between buying the lamp only or the lamp module. More care and attention is necessary when handling bare lamps. Always use gloves or a suitable cloth and ensure the terminals are not over tightened as the ceramic can be cracked and reduce the electronic insulation of the filament. Similarly, if the lamp is under tightened it can causing arcing on the terminal. This will put undue load on the ballast and can lead to lamp failure. Please refer to the operating manual.
Lamp timer
Also known as a lamp counter this feature allows you to check and monitor the number of lamp hours used. Most projectors are fitted with this device.
Lamp uniformity
A level of over 90% is achieved when projector manufacturers utilize lenses positioned approximately 5mm x 5mm. When light from the lamp passes through this configuration light is evenly distributed all over the screen, right up to the corners.
Lux
A standard for measuring light in projectors some years ago. Now the main method of measurement is in ANSI lumens.
M
Metal Halide lamp
The type of lamp used in 90% of projectors. Metal halide is the generic term , some manufacturers the type of metal halide lamp being used such as UHP,UHM, MHE,NSH etc. These lamps typically slowly lose intensity as they are being used. These lamps reach very high temperatures and must be allowed to cool down before handling them. They emit a true white light with a slightly bluish cast.
MHE
A type of metal halide lamp. An abbreviation for Metal Halide Efficiency lamp.
N
NSH
This type of lamp is made of crystalline glass and helps to produce very consistent brightness levels throughout the entire image area.
P
PCP (Polarisation Conversion Prism)
Natural light consists of several elements that diverge in different directions. As this light radiates horizontally, against the projecting direction, it does not add to the brightness of the screen. PCP technology corrects this flaw to virtually double lamp performance and efficiency.
Projector lamp
Also commonly referred to as projector bulb, lampe de projecteur, lampe de rechange, lampe a haute pression, Projektorlampe, Metallhalogenlampe, Metalldampflampe, lampara de proyector, lampada de proiettore, lampada de projecao, projektielampen, beamerlamp, lamppu videoprojektori, metal halide projeckter lampemoduler and projektorlampor.
P-VIP
A type of metal halide lamp. An abbreviation for Premium Video projector lamp.
Q
Quad lamp system
A very small number of projectors for large audiences are equipped with 4 lamps for failsafe operation at all times.
T
Turbo Bright System
Developed by Canon and specifically for brightly lit rooms, the Turbo Bright System increases brightness of projected images by 25%. Most projectors reduce the orange light (wave length 570-600mm) to balance out the colours. In contrast Canon's sophisticated TBS utilises the orange to optimise the light rays from the lamp through the projection lens, without distorting the overall colour balance. The result is clear, vivid projection of text, data and images even in well lit conditions.
U
UHE
A type of metal halide lamp. An abbreviation for Ultra High Efficiency lamp it is well known for low operating temperatures and minimal power consumption less than half of that of halogen bulbs. The lamp is also small in size and has helped to reduce the overall size and weight of projectors.
UHP
A type of metal halide lamp. An abbreviation for Ultra High Performance lamp . Where other lamp types can experience a significant performance and colour shift after a period of time, UHP lamps guarantee virtual constant performance over its lifetime without hotspots. UHP is a trademark of Philips Electronics.
UHB
A type of metal halide lamp. An abbreviation for Ultra High Brightness lamp.
UHM
Common in most Panasonic projectors this high power lamp is a trade mark of Matsushita Electric Industrial Co. Ltd
X
Xenon
A small percentage of projectors use Xenon lamps, mainly high end versions and those used in cinemas. A Xenon lamp produces a more natural colour, stable light, enabling vivid, true-to-life colour reproduction.