This glossary provides a definition of the terminology that you will encounter when choosing your projector or projector lamp. Should you be unsure of anything, please do not hesitate to contact JPUK on 0870 444 3733.

A

Analogue
Analogue video signals use variable voltage which will equal pixel value rather than digital pulses. Digital signals will produce better video.

ANSI
This is the ‘American National Standards Institute’ and is the official organisation that will approve all lighting formats used in projector lamps and projector units.

ANSI lumens
ANSI lumens mean the level of the illumination and brightness available from a projector's display which has been measured in ‘candles.’ For example, a projector that provides 2000 ANSI lumens is producing twice the brightness of a projector with 1000 ANSI lumens. The brightness of a projector will depend on the projector lamp installed. A projector that has been fitted with a new projector lamp will be brighter than an older projector lamp which is likely to dim over time.

Aspect ratio
The aspect ratio means ratio of width in relation to the height of a projected image. There are two aspect ratios which are most used and these are 4:3 and 16:9. A projector unit that projects an image that is a 4:3 aspect ratio equates to the same ratio as your TV or computer monitor. A projector that has a 16:9 aspect ratio capability is known as "wide-screen format". This aspect ratio equates to a theatre or movie screen.

Auto balance
Occasionally errors may occur in the colour balance of black and white parts of the image. Auto balance will adjust black and white levels automatically.

B

Built-in loop through
This facility on your projector unit will allow an additional projector or screen to be connected to display the same signal. This becomes an important facility when using a projector for business or educational presentations and allows the presenter to view a smaller screen, whilst allowing the main projector to present a larger image to the rest of the audience.

C

Chrominance
This refers to the hue and colour saturation.

Colour temperature
This means the amount of "whiteness" that exists in a light source. Metal halide projector lamps will contain higher colour temperatures than halogen lamps.

Component video
This means the best quality video image possible. Component cables divide the image projected into 3 separate colours to provide the best picture possible. Composite cables are the red, yellow (video) and white (audio) standard connections that come with most game systems.

Composite video
This refers to the standard RCA jack for video which will include a yellow plug which provides a video signal that is analogue. This is one of the most commonly found A/V connections but is not the best.

Compression
This is what converts one resolution to another. A projector unit with SVGA resolution will accept XGA resolution compressing it to SVGA which results in a clearer image.

Contrast ratio
This is the ratio of brightness to darkness. Most LCD projectors provide a contrast ratio of 400:1. With contrast ratio the lumen output of a white projected image will be 400 times higher than a projected black image.

D

Dichroic
This is the lens or mirror in a projector unit which reflects wavelengths of light separating the white light into green, red and blue.

Digital signal
This is produced in infinite variations at rapid speed transmitting computer information. Many projectors will utilize analogue signals whether it is from the composite, component or RGB cables.

DLP
This means Digital Light Processing and has been developed by Texas Instruments and is display technology which utilises mirrors for displaying an image. Big advantages with DLP technology used in projector units is that it provides the ability to produce extremely high contrast ratios along with new super light projectors. The disadvantages of using DLP are that colours may not appear as vibrant and saturated.

DVI
This is Digital Visual Interface and refers to digital interface that occurs between PCs and projectors. A projector with DVI is able to provide digital to digital connection without using analogue; a digital connection is preferable to analogue.

E

Eco-Mode Technology
This is a high efficiency projector feature which doubles projector lamp life and provides a quieter operation. This newer innovation eliminates the need for frequent projector lamp replacement and saves money along with being friendlier to our environment. The brightness of the projector lamp is reduced when the projector is in eco-mode.

F

Focus
Projector focus will allow you to tune the maximum and minimum image distances. Many projectors these days provide an Auto Focus setting which automatically focuses the image for you although there will be a manual option.

G

H

Halogen Projector Lamps
Older projector units use halogen projector lamps. A halogen projector lamp provides a yellow light. Halogen projector lamps are less costly but have a shorter life expectancy.

HDMI
This is High Definition Multimedia Interface and is the best connection available. This means a 19-pin digital connection which can transmit a high definition video signal along with an audio signal through a single cable. An HDMI cable is required for any HD devices including projectors, laptops and TV's it provides the best sound and picture quality possible.

Horizontal / Vertical Lens Shift
This is a feature on your projector unit which provides precise image position which leads to speed of installation and easy usage. A projector with this facility may be positioned in a cage or mount and the picture can be adjusted accordingly for image precision.

I

Interface
This is the connection of various elements within your projector unit that work together to convert the signal.

J

K

Keystoning
A projector that has automatic keystoning will mean it is able to uniform an image by correcting the picture it's projecting if the picture is projected onto a surface that is angled.

L

LCD
The Liquid Crystal Display which converts a projector’s colour spectrum into green, red, and blue through three glass panels; light passes through the panels creating the image onto a screen. The majority of projector units will be DLP or LCD. Projectors with LCD provide sharper video imagery and better colour saturation providing greater light efficiency. The result is a richer quality of image.

Lumens
Lumens are measurement of light. The higher a lumen count the brighter the projected image. ANSI lumens means the term used when referring to the brightness of projector units and projector lamps.

Luminance
This means the colour intensity of a picture or image.

M

Metal Halide Projector Lamp
The majority of LCD projector lamps will use a metal halide source, which provides a white light.

Module (projector lamp)
Projector lamp module is a term given to a projector lamp. The module will consist of the plastic housing and actual light bulb along with associated power connections. To fit a bare projector bulb into a projector unit requires a certain amount of technical experience and can be very time consuming. JPUK only sell projector lamp modules for ease of installation, although we refer to these as; projector lamp, projector bulb or projector lamp module on our site.

N

NSH - New Short-Arc High Pressure
This is a lamp which is made out of crystalline glass, which helps produce extremely consistent brightness levels throughout the entire area of the image.

NTSC
This is the National Television Standards Committee and is America’s video transmission system. The majority of Europe uses the PAL system.

O

P

PAL
This means Phase Alternating Line and is a video transmission system which is most commonly used in Europe. The NTSC system is used in America.

Pixel
Pixels are the dots that represent elements of a picture display. The higher number of pixels, the more elements there will be of individual colour and the clearer and more detailed an image will appear.

Polysilicon
This is a material which is used in manufacturing LCD screens. It provides better contrast ratio and a faster response time than TFT LCD screens.

Q

R

Resolution
This is the number of pixels or dots that a display will use when creating an image. As an example SVGA resolution will be 800 x 600 pixels (800 pixels is width of screen and the 600 pixels is the height of the screen), XGA resolution is normally 1024 x 768. The higher that the resolution is the clearer and sharper and image will be.

S

Scan converter
This exists inside the projector unit and is responsible for converting a digital signal from a video or computer allowing the image to appear on a video projector or TV monitor.

Screen Gain
This term describes the extent at which a screen can convert projected image brightness. As an example, a screen gain of 1.3 will ensure a projected image is 30% brighter than a screen gain of 1.0.

Short throw lens
This is necessary if you need to project a large image from a short distance. Most projector units possess an average throw lens, although some recently launched projector models will have a built-in short throw lens.

SVGA Resolution
This means Super Video Graphics Array and if a projector unit has this it will project images at 800 pixels wide by 600 pixels high. This is the lowest resolution projector that you can buy. SVGA projectors are better with PowerPoint presentations and any presentations that have larger images and fonts.

T

Throw distance
This is the distance from the central point of a projector lens to the central point of the screen it is projecting onto. A projected image that needs a longer throw will require a brighter projector.

U

UHB - Ultra High Brightness
This is a type of Metal Halide projector lamp.

UHP - Ultra High Performace (also known as Ultra High Power and Ultra High Pressure)
UHP or Ultra High Performance, are mercury-arc projector lamps that were first developed by Philips in 1995. They are unlike other mercury vapor lamps that are used, which are metal halide lamps, as these lamps only use mercury.

UHE Projector Lamps
This means Ultra High Efficiency and is a form of metal halide projector lamp. UHE projector lamps are known for their ability to operate at low temperatures using minimal power consumption. UHE projector lamps are smaller than other projector lamps which fits lighter and portable projector units.

UXGA Resolution
This is Ultra Extended Graphics Array and means that the projector has a resolution capability which can project images at 1600 pixels wide by 1200 pixels high. This is feature that has limited use but works with specialised applications that are used in the military or medical professions. Projector units with UXGA are expensive.

V

Ventilation
Projectors must be ventilates to allow airflow via the unit’s internal components which keeps the projector lamp cool preventing it from shattering. The ventilation on a projector will normally be found on the rear or side of the unit. Never block a projector's ventilation apart from shortening the projector lamp life it will damage the projector unit.

VGA Resolution
This is the Video Graphics Array and a projector with this resolution can project an image at 640 pixels wide by 480 pixels high. VGA projectors are older technology and typically projectors with the latest resolution will be referred to as XGA, SVGA, WXGA, and UXGA.

Voltage
This is the unit of electric potential.

W

Wattage
This is how we measure a unit of power. Projector lamps will show their wattage visibly on the glass bulb and it means the level of power consumption from the projector bulb.

WXGA Resolution
This means Widescreen Extended Graphics Array and projectors with this resolution are able to project images of 1280 pixels wide by 768 pixels high. WXGA resolution is a step up from XGA resolution. A projector with WXGA resolution can display a widescreen XGA image because the height is the same as XGA but the width of pixels is greater.

X

XGA Resolution
A projector with XGA resolution means it can project images of 1024 pixels wide by 768 pixels high. A projector with XGA is a step up from SVGA resolution. XGA resolution provides clearer and better quality images.

Y

Z

Zoom lens
High end projectors often feature a zoom lens which provides ability to adjust focal length. Zoom lenses may be digital or manual.