Please select a letter for terms starting with that letter:

- L -

Lamp
The bright source of any projector partially responsible for your sharp, clear image.

LAN
Acronym for Local Area Network; the local area typically being an office building or technology campus. Great for controlling your projector remotely speical network software.

LCD
Acronym for Liquid Crystal Display; liquid crystals exist in an intermediate state between liquid and solid, and realign under electrical stimulation. Exceptionally slim and lightweight, they are ideal in word processor, computer, and TV displays.

Lumen
A measurement of the amount of visible light energy that comes from a light source and is perceived by the eye.

Lamp
Lamps have different color characteristics in terms of just what color of white light they emit. Incandescent lights all tend to emit a continuous spectrum of light (light which contains all colors), with a tint towards just one color. Tungsten-halogen, or quartz lamps, are generally considered to emit white light in the 3200K to 3400K range. The everyday incandescent light bulb is reddish in color, and has a color temperature in the 2800K range. There are a number of other types of lamps available. They are not used in designs, because many are deficient in certain areas of the color spectrum, and are inappropriate for use in a display environment.

• Low Pressure - The low-pressure sodium lamp has the highest lamp efficacy of all sources, but it is monochromatic yellow. The light-producing element is an arc tube. The arc tube contains a small amount of argon and neon to aid in starting the lamp. The bulb is made of ordinary glass. It acts to maintain a constant environment for the arc tube.
• High Pressure - High-pressure sodium lights also use an arc tube. The arc tube is small in diameter to maintain a high operating temperature. The arc tube is made of a ceramic material.
• Vapor - Mercury vapor lamps use a light-producing element that is in an arc tube. The arc tube is constructed of quartz to allow ultraviolet radiation to be transmitted. The arc tube contains mercury and small quantities of argon, neon, and krypton.
• Halide Lamps
  Metal halide lamps use a light-producing element that is an arc tube. The arc tube has the same construction and operating principles as the mercury lamp. The color of the metal halide is balanced across the spectrum. By improving the color without the need for a phosphor coating, the lamp approaches a point source that will result in better potential for optical control.

LAN
Acronym for Local Area Network. A system that connects two or more microcomputers to allow users to share resources and communication.

Lancia
An NTSC/PAL/SECAM to IDTV line doubler with motion mode interpolation.

Laptop
Portable computer-larger than a palm top but smaller than a desk top.

Laser
Light Amplification by Stimulated Emission of Radiation, often used for laser pointers.

LCD (Liquid Crystal Display)
A device that displays text and graphics on a flat screen that uses no projected light or illumination.

LCD Panel
A device used to project video images through a Liquid Crystal Display and an overhead projector onto a large screen.

LED
Light Emitting Diode, a semiconductor diode that converts electrical energy into visible light. Often used in VCR and other equipment displays.

Lenticulation
A cylindrical lens which causes light passing through it to be dispersed perpendicular to its axis.

Lenticular Screen
A large series of parallel lenticulations cut vertically into the screen surface to improve horizontal dispersion. Manufacturers of screens include: Sterwart Filmscreen and Da-Lite.

Level Control
The Level Control on selected Extron interface products is similar to the Contrast Control on a data monitor. It can either increase or decrease the output voltage level of the interface to the connected data monitor or projector. This results in greater or less contrast in the picture.

Light Valve
A device the light transmission of which can be varied in accordance with an externally applied electrical voltage, current, an electronic magnetic field, or an electron beam.

Linearity
The ability of a display device to produce the an object the same size anywhere on the screen, e.g., Poor linearity may show a line of text at one size when it is at the top of the screen, but at a different size when the same line of text is at the bottom of the screen.

Line Doubler
An Increased Definition Television unit that doubles the number of scan lines in a video picture. This fills the space between the original lines, making them less noticeable.

Logic
A sequence of operations performed by hardware and software. Hardware logic refers to the memory chips and electrical circuits that perform the controlling operations of a computer. Software logic, also called program logic, is the sequence of instructions in a particular program.

Low Impedance
The condition where the source or load is at a lower impedance than the characteristic impedance of the cable. Low source impedance's are common; low load impedance's are usually fault conditions.

Loop Through
In most projector, the video input section includes a signal path that bypasses most of the internal circuitry and "loops through" the signal, buffered and sent back out to make it available to be displayed by another display device (e.g., CRT monitor).

Low-Level Language
A programming language, also referred to as an assembly language, where each statement translates into a single machine instruction.

Lumen
A measurement of quantity of light taken at the source of the light. Lumens per square foot are foot candles. See Lux.

Luminance
The signal that represents brightness in a video picture. Luminance is any value between black and white. Luminance is abbreviated as "Y".

Lux
The amount of light per square meter, incident on a surface. The metric measurement of light quantity. The measurement is taken from the reflection off the object illuminated. One foot-candle equals 10.76 lux. A lux equals one lumer per square meter. 1 lux = 1 lumen/square meter = 0.093 foot-candles.

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