
GLOSSARY OF TERMS
Active display area – Where the image is
displayed or face of the CRT.
A/D - Analog to digital conversion (or converter). Used at
transmission end of broadcast.
Addressable Resolution - The highest resolution signal that a
display device (TV or monitor) can accept. The device, however, may
not be capable of displaying this resolution.
Advanced Television Systems Committee - Also known as ATSC,
the committee responsible for digital television standards and
development, as well as all 18 formats of DTV.
Analog TV - "Standard" television broadcasts analog TV.
Analog signals vary continuously, representing fluctuations in color
and brightness.
Anti-static - An adjective describing the class of materials
which includes conductive materials that do not allow an electrical
field to be built up or stored upon themselves. With an anti-static
coating on the monitor’s CRT surface, no static electricity is built
up, therefore, upon touching the CRT the end-user is not shocked and
there is reduced dust build up.
Application - specific integrated circuit - ("ASIC") refers
to an integrated circuit uniquely designed and fabricated for a
particular product application. Highly sophisticated electronic
products can be economically produced where high production volumes
justify the initial integrated circuit design and tooling costs.
Artifacts - Unwanted visible effects in the picture created
by disturbances in the transmission or image processing, such as
'edge crawl' or 'hanging dots' in analog pictures, or 'pixelation'
in digital pictures.
Aspect Ratio - Refers to the width of a picture relative to
its height. If an NTSC picture is 4 feet wide, it will be 3 feet
high; thus it has a 4:3 aspect ratio. HDTV has a 16:9 aspect ratio.
ATV - "Advanced Television" is an earlier term used to
describe the development and advance applications of digital
television, now simply referred to as DTV.
Augmented Reality - or Enhanced Reality refers to a display
in which simulated imagery, graphics, or symbology is superimposed
on a view of the surrounding environment.
Barrel - the appearance of curved edges of the display image
outwards. See pincushion.
Bandwidth - For monitors, bandwidth refers to the highest
signal frequency a monitor’s circuit can display. The higher the
bandwidth, the higher the resolution and the sharper the image will
be.
Beam - The electron beam in the CRT, which makes contact with
the phosphors on the CRT surface, activates them and causes them to
produce different red, green and blue light depending on the
phosphor.
Brightness - refers to the attribute of a visual sensation by
which a stimulus appears more or less intense or appears to emit
more or less light. (Brightness is not a photometric standard and
should not be used in conjunction with photometric units such as
foot lamberts.)
Channel - A 6 Mhz (bandwidth) section of broadcasting
spectrum allocated for one analog NTSC transmission.
Composite Video - An analog, encoded video signal (such as
NTSC) that includes vertical and horizontal synchronizing
information. Since both luminance (brightness) and chrominance
(color) signals are encoded together, only a single connection wire
is needed (i.e. RCA cables).
Component Video Connection - The output of a video device
(such as a DTV set-top box), or the input of a DTV receiver or
monitor consisting of 3 primary color signals: red, green, and blue
that together convey all necessary picture information. With current
consumer video products, the 3 component signals have been
translated into luminance (Y) and two color difference signals (PP,
PR), each on a separate wire.
Composite Video Output - The monitor receives only one signal
from the computer. The monitor must then decode the signal to
determine and separate red, green and blue sync signals that can
then be produced by the monitor.
Compression - A method of electronically reducing the number
of bits required to store or transmit data within a specified time
or space. The video industry uses several types of compression
methods but the method adopted for DTV is called MPEG2.
Contrast - refers to the ratio of the brightest part of an
image versus the darkest part of an image (for example, 100:1).
Convergence - The color monitor’s ability to scan the three
electron beams (red, green and blue) onto a single point and thus
producing a white dot.
Color Wheel - Central to DLP technology’s unique color
filtration process, the color wheel is a small rotating disk
composed of red, green and blue filters. The DMD (digital
micromirror device) briefly creates an image for each color. The
viewer’s eye combines these images to form a complete picture.
Because the color wheel rotates at speeds exceeding 120 revolutions
per second, it is impossible to distinguish the individual color
images.
CRT - Cathode Ray Tube
CRT Projectors - A front projection method similar to LCD,
CRT (cathode ray tube) projectors output three identical images in
red, green, and blue. The three images are then combined to create
the final projected image.
Digital Television (DTV) - Refers to all formats of digital
television, including high definition television (HDTV), and
standard definition television (SDTV). Also referred to as ATV
(advanced TV).
Digital Light Processing (DLP) - DLP™ technology delivers the
clearest, sharpest, brightest, most accurate images in a broad range
of projection and display applications including business
projectors, home entertainment projectors, large screen tabletop
TVs, video walls and projection systems used in commercial
entertainment. DLP Cinema™ technology, which delivers large screen
images that are superior in many respects to film, is helping to
revolutionize the movie industry.
Digital Micromirror Device (DMD) - The Digital Micromirror
Device is an optical semiconductor chip populated with more than a
million hinged, microscopic mirrors which operate as optical
switches to create a high resolution, full-color image.
DILA Projectors - Short for Digital Direct Drive Light
Amplifier, DILA projectors employ microchip technology to create
high definition pictures. The DILA chip integrates an improved fixed
matrix display technology designed to reduce grid patterns and
produce a bright picture.
Direct view display - refers to a display viewed without aid
of additional optics or magnification by the unaided eye of the
user. The size of the image produced by the display is the actual
size viewed by the user.
Display format - refers to display addressability (e.g., 640
x 480), aspect ratio (e.g., 4:3), or video standard (e.g. VGA).
DLP Projectors - DLP (Digital Light Processing) projectors
are the future of home theater projectors. DLP-based projectors are
among the brightest, most reliable projectors in the industry.At the
heart of DLP technology is the Digital Micromirror Device (DMD)
optical semiconductor chip. The DMD switch has an array of up to
1,310,000 hinged, microscopic mirrors that operate as optical
switches to create a high-resolution image.
DTS - Digital Theater Systems sound. Discrete 5.1 channel
surround system similar but not the same as Dolby Digital. Dolby
Digital is the DTV standard, but DTS competes with it on DVD and in
the movie theaters.
Dot Pitch - The distance of one phosphor dot to the nearest
dot of the same color on the adjacent line.
Downconvert - A term used to describe the format conversion
from a higher resolution input signal number to a lower display
number, such as 1080i input to 480i display.
DVD Player (Digital Video Disc) - An integral part of many
home theater systems, DVD players use digital technology for a
quality viewing experience. DVD movies generally contain features
including Dolby Digital Sound, several language tracks, and wide
screen or normal viewing options on a single DVD-video disc.
Electronic Guns - The device in the CRT that produces the
electron beam that is attracted to the phosphors on the face of the
CRT; this activates the phosphors thus causing them to emit red,
green or blue light.
Electrostatic - Stand alone electronically charged particles
that build up on the CRT surface.
ELF - Extremely low frequency. For magnetic fields and
alternating electric fields, the ELF fields range from 5Hz to 2Khz.
Emission - The emitting of different types of radio
frequencies, magnetic fields and light.
Emissive displays - refer to a broad category of display
technologies which generates its own light. Emissive display
technologies include organic light emitting diodes,
electroluminescent, field emission, plasma, and vacuum fluorescent.
In contrast non-emissive displays require a separate, external
source of light (such as the backlight of a liquid crystal display).
EPG - Electronic program guide. An on-screen display of
channels and program data.
Ergonomic - Applies biological and engineering solutions to
problems relating to the individual and their working relationship
with machines.
FCC - Federal Communications Commission. The U.S. commission
regulates the radio frequencies over the airwaves.
Field emission display ("FED") - refers to a flat vacuum tube
display built with a multitude of tiny electron guns (micro-tip
emitters) placed in a high vacuum environment. Its operation is
similar to that of the CRT, in which electrons from a cold cathode
are focused on a screen to create an image. Emission of electrons
from the cold cathode occurs in response to an applied voltage.
Field emission - refers to the release of electrons from a
surface when it is subjected to a very strong electric field.
Field of View (FOV) - describes how large the virtual image
can appear to be to the viewer and is measured in degrees. >50
degree FOV per eye is possible using OLED microdisplays.
Flat-panel display - refers to video displays used in lap top
computers and other devices where the monitor is desired to be as
thin as possible.
Frequency - The number of times per second that a signal
fluctuates. The international unit for frequency is the hertz (Hz).
One thousand hertz equals 1 KHz (kilohertz). One million hertz
equals 1 MHz (megahertz). One billion hertz equals 1 GHz
(gigahertz). Television is broadcast in frequencies ranging from 54
MHz to 216 MHz (VHF) and 470 MHz to 806 MHz (UHF).
Frequency Range - the high and low limits of the frequencies
that can be used with your monitor. Usually pertains to horizontal
and vertical sync ranges.
Full-scan - The Capability to increase the size of the image
to the edge of the monitor bezel.
Front Projection TV - Front projection is a method of viewing
that utilizes a video projector from the ceiling. The image is
projected onto a separate unit, typically a retractable movie
screen. The front projection method allows for projection onto
screen sizes that can exceed 300 inches. Front projection methods
include DLP, CRT and LCD.
Head-mounted display - or helmet mounted display ("HMD") or
Head-wearable display ("HWD") refers to a diverse family of viewing
systems where one or more displays and sets of optics are attached
to the head (head-mount display) or an accessory. For example, they
can be designed into helmets, hardhats, or eyeglasses. Images can be
projected into one eye (monocular) or both eyes (binocular).
High Definition Television (HDTV) - The generally agreed upon
definition of HDTV is approximately twice the vertical and
horizontal picture resolution of today's NTSC TV, which essentially
makes the picture twice as sharp. HDTV also has a screen ratio of
16:9 as compared with most of today's TV screens, which have a
screen ratio of 4:3. HDTV offers reduced motion artifacts (i.e.
ghosting, dot crawl), and offers 5.1 independent channels of
CD-quality stereo surround sound, (also referred to as AC-3).
Home Theater Receiver - The receiver is the heart of home
theater systems, typically consisting of an amplifier, decoder,
AM/FM tuner, audio/video switcher, and decoder.
Home Theater Screen - The home theater screen is what an
image is projected onto. A high-quality screen contributes to a
crisp, clear image. Front projection systems require a separate home
theater screen to be utilized.
Home Theater System - A home theater system refers to a group
of electronics set up in one’s home for the presentation of
high-quality images and sound. Electronics that are typically found
in home theater system setups include a VCR, stereo television or
HDTV, receiver, and DVD.
Horizontal Frequency - The inverse of the time it takes for a
monitor to scan from the beginning of one line to the beginning of
the next line; typically stated in kilohertz.
Interlaced Scanning - In a television display, interlaced
scanning refers to the process of re-assembling a picture from a
series of electrical (video) signals. The "standard" NTSC system
uses 525 scanning lines to create a picture (frame). The
frame/picture is made up of two fields: The first field has 262.5
odd lines (1,3,5...) and the second field has 262.5 even lines
(2,4,6...). The odd lines are scanned (or painted on the screen) in
1/60th of a second and the even lines follow in the next 1/60th of a
second. This presents an entire frame/picture of 525 lines in 1/30th
of a second.
Invar Shadow Mask - A monitor technology where light is
emitted through a heat resistant metal sheet containing numerous
holes. Basically, this thin sheet of metal has holes corresponding
to each phosphor dot on the CRT and causes the correct red, green
and blue electron gun beam to hit the correct color phosphor.
Image quality - refers to an objective measurement or
subjective rating of the quality of a display system.
KHz (Kilohertz) - A unit of frequency equal to one thousand
cycles per second.
Lambertian - light output means that the intensity of light
is the same in all directions. This permits viewing from many angles
and allows compact lens systems with large exit pupils to be built.
A large exit pupil permits the virtual image to be seen from a
larger range of angles and keeps the image stable as the pupil
moves. Large exit pupil is important for long term ease of viewing
with minimal fatigue.
LCD Projectors - A method of front projection, LCD projection
works by separating the image into red, green, and blue. The colors
are then recombined before the image is projected through the lens.
"LEP" - is an acronym for polymer-based organic light
emitting diodes, derived from "light emitting polymers."
Letterbox - The term used to describe the way a 16:9 aspect
ratio image is displayed on a 4:3 screen, where black areas are
visible above and below the image.
Light emitting diodes ("LED") - refers to a semiconductor
device which emits light when current flows through the device. An
LED is formed when p-type and n-type materials are joined. These
devices have a preferred current direction. When a voltage is
applied, causing electrons to flow through the structure, electrons
flow into the p-type material, and holes flow into the n-type
material.
LCD-Liquid crystal display - refers to a display which uses
liquid crystals with optical polarization properties that can be
altered by an applied electric field. The liquid crystal materials
absorb or transmit light depending on the polarization, and thus
function as "light valves." In an active matrix liquid crystal
display ("AMLCD"), each valve is individually controlled.
Luminance - refers to the amount of visually effective light
emitted by an extended source. Typically expressed in nits,
footlamberts (fL) or candelas per square meter (cd/m2). One fL =
3.43 cd/m2 or 3.42626 nits One cd/m2 = 0.292fL or 1 nit.
Magnetic Field - A state produced in a medium, either by
electrical current flow in a conductor or by permanent magnet, that
can induce voltage in a second conductor.
MHz (Megahertz) - A unit of frequency equal to one million
cycles per second.
Micro-mirror - refers to a display using a large number of
small mirrors which are deflected to direct light toward or away
from the viewer.
Microstructural - refers to structures near to or smaller
than a few micrometers in size.
Microdisplay, or Miniature display - refers to small displays that
are of such high resolution that they are only practically viewed or
projected with lenses or mirrors. Microdisplays are typically
magnified by optics to enlarge the image viewed by the user. For
example, a miniature display smaller than 1 inch in size may be
magnified to provide a 12 inch to 60 inch viewing area.
Monochrome - refers to a display that emits a single hue but
may vary in intensity and saturation. For example, monochrome
miniature displays used in many HMDs are typically green and are
used to display symbology or sensor imagery.
MPR - A rating factor by the Swedish National Board of
Measurement and Testing. This council produces the recommendations
for the magnetic and electrical field emissions guidelines. The
council’s name has been changed to SWEDAC.
Multiscan Monitor - Monitors that are capable of displaying a
range of resolutions or graphics standards having different
horizontal and vertical frequencies.
Nit - refers to a measure of luminance equivalent to 1 Cd/m2,
1fL = 3.42626 nits.
Non-emissive displays - refers to a broad category of
displays which absorb or block light from a separate light source.
Liquid crystal, electrochromatic, electrophoretic, ferroelectric,
and micro-mirror displays fall in this category.
Non-Interlaced(Progressive Scan) - Each line is scanned
during each total vertical (full) screen refresh.
"OEM" - is an acronym for "original equipment manufacturer".
OEMs manufacture components and sub-assemblies which are purchased
by companies which integrate the components and sub-assemblies into
final products.
Organic light emitting diode (OLED) - refers to a type of
display which uses organic material as a diode type light emitting
material. The operating principal of OLED devices is current
injection. For comparison, the operational principal of inorganic
LEDs is collisional excitement due to an electric field. There are
two categories of OLEDs: small molecule and polymer-based.
Personal - Viewer TM refers to Headset Monitor incorporating
a flat panel display that provides data or video images privately to
an individual via a virtual computer screen.
Phosphor - Phosphorescent substance of red, green and blue
that emit light when activated by electrons.
Plasma displays - refer to displays which emit light from
electrically excited gas mixtures. Color plasma displays use
phosphors which absorb ultraviolet light that is generated by
special gas mixtures.
Plasma Flat Panel Television - Ultra-thin plasma television
displays make for easy placement within home theater systems. The
plasma technology allows for brightness, clarity, and a viewing
range of 160 degrees. The flat-panel display consists of millions of
phosphor-coated miniature glass bubbles containing plasma. An
electric current flows through the screen causing certain
plasma-containing bubbles to emit ultraviolet rays, triggering the
phosphor coating to produce the proper color (red, green, or blue).
Pin Cushion - The appearance of curved edges on the display
image inward. Pixel - is a contraction of "picture element" and
refers to a single dot of light that is the smallest individually
addressable unit of an image that can be displayed.
Polymer based OLEDs - refers to a category of organic light
emitting diodes. When a current is passed through a cell, the
polymer's molecular structure is excited, creating light emission.
The output efficiency of this process is within the spectrum from
blue to infrared.
Polymeric display - refers to a display using light emission
from polymers when an electric current is passed through the
material or polymer diode.
Progressive Scan - the way a screen displays the image you
see before you in a full picture per each frame, rather then the
interlaced method in which it shows you the odd lines, then even.
This shows you all lines at once. Ex: Computer Monitor.
Projection TV - Projection TVs create a miniature picture
inside the projector. In rear projection systems, the image is then
shone onto a large screen located within the television unit itself.
Front projection systems instead shine the image onto a screen that
is separate from the television unit.
Resolution - refers to pixel density (number of pixels) or
dot pitch (measured in micrometers or millimeters). Resolution is
typically referenced by Rows x Columns. Commonly used resolutions
include ¼ VGA (240 x 320), VGA (480 x 640), SVGA (600 x 800), XGA
(768 x 1024), and SXGA (1024 x 1280). eMagin using modified
nomenclature by adding a + for its color SVGA+ (852 x 600) and XGA+
(1066 x 768) designs being developed.
"RF" - applications refers to radio frequency, or very high
frequency and millimeter wavelength.
Rear Projection TV - Rear projection is a method of
projection that combines a projector and viewing screen into one
television unit. RGB - refers to red, green, and blue pixel
combinations used to create full color.
"SBIR" - Program refers to the U.S. Government's Small
Business Innovation Research program which promotes the use of small
businesses for research. It is a highly competitive program whereby
small business are awarded research funds targeted for technical
solutions to meet the needs of various Government Departments. The
Company has been awarded more than 5 SBIR programs, and is currently
performing a Phase III program.
Screen Gain - Screen gain refers to a projected image’s level
of brightness on a screen. A low screen gain displays a dark screen
image. Conversely, a bright screen image indicates a high screen
gain.
Set-top Box (DTV STB) - A unit similar to today's cable
boxes, which is capable of receiving and decoding DTV broadcasts. A
DTV 'Certified' STB can receive all 18 ATSC DTV formats and provide
a displayable picture.
Spectrum - A range of frequencies available for over-the-air
transmission.
Standard Definition Television (SDTV) - Digitally transmitted
SDTV includes 480 line resolution in both interlaced and
progressively scanned formats. It offers significant improvement
over today's conventional NTSC picture resolution, and is similar to
DVD or DBS quality because the digital transmission eliminates snow
and ghosts, which can be common with the current NTSC TV format.
Also, thanks to digital compression technology, several programs can
be transmitted simultaneously within the same channel.
S-Video - Separated video. An encoded video signal which
separates the brightness from color data. S-video can greatly
improve the picture when connecting TVs to any high quality video
source such as digital broadcast satellite (DBS) and DVDs.
Subwoofer - A subwoofer is an individual speaker commonly
found in home theater sound systems that processes bass sounds as
low as 15 hertz.
Surround Sound - Surround sound refers to a sound system
arrangement designed to literally “envelop” the listener with sound.
UHF - Ultra high frequency, the range used by TV channels 14
through 69.
Upconvert - The term used to describe the conversion of a
lower apparent resolution to a higher number, such as "upconverting"
720p to 1080i. This is a misnomer, though, since to accomplish this,
the horizontal scanning frequency is actually lowered from 45kHz to
33.75kHz. Resolution quality is not improved by this method.
Vacuum fluorescent - display refers to a display using hot
wire electron emission which is directed toward a cathodoluminescent
phosphor to emit light. These displays are found in some clock
radios and automobile indicators.
VHF - Very high frequency, the range used by TV channels 2
through 13.
Viewing Angle - A screen’s viewing range indicates the
maximum angle that an image can be viewed at from an off-center
point.
Virtual reality ("VR") - or artificial reality refers to an
electronic system which is designed to create a simulated
environment around the viewer. Such as system must be interactive
with the user to be considered true VR.
Y, PB, PR - Generally used where a digital TV signal source
is employed. The video signal is separated into its component parts
of brightness and color differentials. The most advanced method for
interconnecting decoded video data.
Y, U, V - Also sometimes referred to as Y, Cr, Cb, where a
video signal is separated into components of brightness and color,
arguably to a degree more advanced than S-video |