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Lacquer
A type of clear finishing material similar to varnish and preferred by sign
makers because of its abilities to dry quickly and not be affected by the presence
of dust.
Lambert
A unit of measure of light luminance.
Laminate
A process by which different materials are layered and then bonded together
using adhesion. The end result may be the creation of a substrate such as
medium density overlay (MDO) or the protection of the underlying surface,
as when a clear plastic film is laminated to a decorated surface.
Lampbank
Columns or rows of lamps. Also used to refer to the part of larger message
centers that the public sees; columns and rows of lamps.
Lamps
Light is produced by lamps but, because of they are made as long thin tubes,
most discharge lamps used by the sign industry are referred to as "Tubes".
Landscape format
Proportion of a sign in which height is appreciably shorter than width.
Lap joints
Method of making overlapping vertical joints in acrylic panels. Usually used
with supporting clear reinforcement.
Laser
Stands for Light Amplification by Stimulated Emission of Radiation. An intense
light beam with a very narrow band width gaining popularity as a tool for
engraving and cutting.
Layout
The total arrangement of a sign`s graphics. Shows the overall plan of how
the artwork and copy will be arranged on the face.
LCD (liquid crystal display)
A type of electronic sign utilizing liquid crystals that become opaque or
clear when exposed to a controlled voltage. Although LCD`s are most common
in calculators and digital watches, they are also used in some time and
temperature displays.
Lead coated Steel
Sheet steel treated with a lead coating and once used extensively in the sign
industry for its rust resistance and soldering qualities. Not used in large
quantity today because of the same lead coating.
Lead glass
So called because it contains around 25% lead oxide and popular in most parts
of the world for use in the manufacture of cold cathode tubes and in particular
the electrodes.
LED (light emitting diode)
A type of electronic sign that utilizes hundreds of light emitting diodes
electronic chip and colored lens assemblies in single and tri-color matrixes.
LED`s are physically flexible and inexpensive to operate when compared to
other message centers.
Legibility
The characteristics of letters, numbers, graphics, or symbols that make it
possible to differentiate one from the other. See Conspicuity. The
quality of a sign`s typefaces that allows it to be easily read and deciphered.
(See readability).
Letter space
Horizontal space between characters.
Light emitting diode
(See LED).
Light Output Ratio
The ratio of the total light emitted by a luminaire (light fitting) to the
total light output of the lamp or lamps it contains. It is always less than
1.
Line space
Vertical space between adjoining lines of text.
Listed Sign
A sign labeled to indicate that the manufacturer of the sign is identified
in a list published by a National Recognized Testing Laboratory as producing
signs in conformance with the applicable American National Standard.
Liquid crystal display
(See LCD).
Live
An electrical circuit which is electrically charged.
Live part
A conductor or conductive part intended to be energized in normal use, including
the neutral conductor but, by convention, not a P.E.N conductor.
Logo
A design that represents goods, identity or service. Traditionally,
any group of type characters (3 or more characters) such as a company name
or product name linked or grouped and displayed in a fixed format and not
to be confused with company symbols, abstract or pictorial. The term is currently
used to describe any design or symbol, with or without supporting lettering,
prepared for a corporation or organization which forms the centerpiece of
its corporate identity.
Low voltage
A voltage normally exceeding 50 V a.c. or 120 V whether between conductors
or to earth, but not exceeding 1000V a.c. or 1500 V d.c. between conductors,
or 600 V a.c. or 900 V between conductors and earth.
Lower case letter
Letter in an alphabet other than an upper case (capital) letter.
Lumens
The standard measure of light radiation. (For example, one candle emits 12.5664
lumens).
Luminance
A measure of the brightness of a sign. It is usually applied to signs with
a significant surface area (not point sources) and is expressed in terms
of Candelas per Square Meter.
Luminance Ratio
Any sign face will have parts which have a higher luminance than other parts.
The ratio of the luminance of the brighter parts to that of the less bright
parts is called the luminance ratio. If this is too large, the illumination
of the sign face will appear patchy.
Luminescence
The quality of giving off light by the absorption of radiant energy. Used
to describe any cold light.
Luminous (discharge) tube
Another name for a neon tube. A luminous tube consists of a sealed glass vacuum
tube with an electrode at each end containing a specific gas. As an electrical
current is passed between the electrodes, the gas is ionized and emits light.
The color of the light is determined by the gas and phosphor, which the
tube contains.
Luminous efficacy
The lumen output of a lamp per Watt of power it consumes.
Luminous flux
The total light emitted by a source or falling on a surface. The unit of light
is the lumen.
Luminous Intensity
The luminous flux in a given direction (from a reflector lamp, for example).
The unit is the candela (one lumen per steradian).
Lux
(See lumens). |
