actual image size
The size of the display on the screen is dependent upon the signals provided by the video
card. The displayable diagonal measurement can vary, depending on how the graphics mode is
generated and how the monitor responds to the characteristics of the video signal.
Aperture grille technology employs a series of thin, closely spaced vertical wires to
isolate pixels horizontally. The pixels are separated vertically by the nature of the scan
lines (beams) used to compose the image.
A technique used to make LCDs easier to read.
A measure of the display performance of a monitor. Expressed in MHz, bandwidth is the
number of dots that can be displayed in a line per second. More strictly, it is the
frequency response of the system between points where the signal level falls to a
specified percentage of its maximum value (usually 50% or 75%). In principle, the greater
the bandwidth, the better the monitor-although the quality of the picture tube is often
the limiting factor affecting display performance, and for many standard monitors there is
little point in increasing the bandwidth beyond a certain point. Typical bandwidths for monitors
(Spring 2003) are as follows:
VGA monitors: 18 MHz
FGA+ monitors: 35 MHz
CAD monitors: 100 MHz
Component products can be Bauart certified by TUV for expected safety
concerns, meaning evaluation to German and European Union standards for
building in to other equipment. Typical component products are touchscreens,
controllers, and kiosk or frame touchmonitors.
Light output measured at the faceplate of the CRT; typically measured in footlamberts
(Fl). A minimum brightness level of 20 Fl when viewing a full-sized page is considered
Compact Disc Read-Only Memory. A CD-ROM is any compact disc that
contains computer data. "ROM" means that you cannot save
information onto these discs. These discs can hold huge amounts of data
(up to 640 megabytes). If there is a large amount of data on a CD-ROM,
then it is usually impractical to copy the data onto the hard disk; in
this case, you must insert the disc into the drive whenever you want to
use the data. CD-ROM may also refer to the drive used to read these discs.
The CE (Conformite Europeene) marking on end products indicates
compliance with all applicable directives. For information technology
equipment (ITE), this typically means Low Voltage Directive 73/23/EEC (LVD),
and the EMC Directive 89/336/EEC. Typical end products are desktop
touchmonitors. Components typically do not carry
the European Union's CE marking. Properly applied, they will comply with
the LVD and EMC Directives. Typical component products are touchscreens,
controllers, and kiosk touchmonitors. Refer to the product Declaration
of Conformity (DOC) for test levels.
The ratio between the maximum and the minimum brightness of the display.
A manual gain control for a monitor, affecting both luminance and contrast.
A trademark registered to the Australian Communications Authority,
indicating compliance with the electromagnetic radiation emissions limits
of Australia and New Zealand.
Cathode ray tube. Also known as picture tube or screen. A picture tube in
a TV is also a CRT.
Display Data Channel. A VESA standard for communication between a monitor and a video
adapter. Using DDC, a monitor can inform the video card about its properties, such as
maximum resolution and color depth. The video card can then use this information to ensure
that the user is presented with valid options for configuring the display.
VESA standard bi-directional digital data channel between the display and the host. The
host initiates data transfer by reading the EDID from a memory location in the display.
also DDC and EDID.
Microprocessor-based digital control of picture parameters and video modes for complete
control of picture settings and modes and instant recall of all settings at the push of a
button. This very advanced feature allows the user to switch to any required
mode at any instant without having to spend time readjusting the picture.
The distance between one phosphor dot (i.e. red, green, or blue) and the
nearest phosphor dot of the same color in the line above or below.
Display Power Management Signaling. A VESA standard that ensures that monitor and
video card manufacturers produce power-saving products that work together.
Any data storage device including CD-ROM drive, floppy disk drive, and hard disk drive.
Extended Display Identification Data. A VESA standard for data structures containing the
display identity and the basic display specifications.
electronic radiation standards
International standards established to limit electromagnetic emissions from monitors.
There are currently two important standards, both derived from regulations originally laid
down by the Swedish authorities. See also MPRII, TCO95,
Electromagnetic compatibility. EMC requirements stipulate that a device shall not cause interference within itself or in
other devices, or be susceptible to interference from other devices. The European Union was the first governing
body to establish laws (CE) regarding immunity of devices from EMI. See also CE, EMI, and RFI.
Electromagnetic interference. This interference in the operation of a device is caused by incompatibility with ambient
signals. Common sources of EMI include transmitters and receivers (radio, TV, cell phone), power mains (lightning,
surges, brownouts), appliances, computer oscillators, and electrostatics. Many countries have established laws (such
as FCC and CE) governing EMI source limits. See also CE, FCC
Class A, FCC Class B, EMC, and RFI.
A voluntary partnership between the U.S. Department of Energy, the U.S.
Environmental Protection Agency, product manufacturers, local utilities, and retailers.
ENERGY STAR labeled products use less energy than other products. Partners help promote
efficient products by labeling with the ENERGY STAR logo and educating consumers about the
benefits of energy efficiency.
FCC Class A
A marking FOR OFFICE USE means the design has been tested for compliance with the U.S. Federal
Communications Commission's (FCC) Part 15 Class A RF emissions limits, and is suitable for use in nonresidential
settings. Industry Canada's RF emissions limits are identical to the FCC's. See also IC Class A.
FCC Class B
A marking FOR HOME OR OFFICE USE means the design has been tested for compliance with the U.S. Federal
Communications Commission's (FCC) Part 15 Class B RF emissions limits, and is suitable for use in residential or
nonresidential settings. Industry Canada's RF emissions limits are identical to FCC's. See also IC Class B.
flat panel displays
flat square screen
A screen that is flatter and squarer than the conventional CRT screen. The flatter outline
reduces picture distortion and ambient reflections, and allows better use to be made
of the screen area.
Condition of the display caused by the mismatch of vertical and horizontal refresh rates,
when a phosphor's illumination begins to decay prior to being refreshed. The resulting "flicker"
is particularly detectable with peripheral vision. Flicker can be
eliminated by increasing the refresh rate to a value at or above 70 Hz.
frequently asked questions
A list of questions/answers provided by companies related to their products or Web site.
A German certification, Geprhfte Sicherheit ("tested safety"). End products can be GS-certified by TUV for expected
safety concerns, meaning they have been evaluated and have met German standards. Typical end products are
A storage device inside a computer, generally designated as the C: drive. It cannot be seen without opening up the
computer; however, usually a light on the front of a computer shows when the hard disk is being accessed.
The unit of frequency named after the physicist Heinrich Hertz
(1857-1894). One hertz (Hz)
is equal to one cycle/second.
The time it takes to scan each of the horizontal lines that make up the display; measured in
kilohertz (kHz). Horizontal frequency is directly related to the vertical refresh rate, so
that the greater the number of vertical lines, the higher the horizontal frequency
horizontal scanning frequency
The number of video lines written on the screen every second (from left to right); also
called line frequency and expressed in kHz. The higher the horizontal scanning frequency,
the higher the resolution and/or the refresh rate, which produces a more
stable image, helping to reduce user fatigue and stress.
I2C bus: access bus
A standard-protocol two-wire (clock and data) serial data bus.
IC Class A
A Class A compliance statement means the design has been tested for compliance with Industry Canada's ICES 03
Class A RF emissions limits, and is suitable for use in non-residential settings. Industry Canada's RF emissions limits
are identical to the FCC's. See also FCC Class A.
IC Class B
A Class B compliance statement means the design has been tested for compliance with Industry Canada's ICES 03
Class B RF emissions limits, and is suitable for use in residential or
nonresidential settings. Industry Canada's RF
emissions limits are identical to the FCC's. See also FCC Class B.
interlaced scanning mode
A scheme that takes two passes to paint an on-screen image, painting every other line on
the first pass and sequentially filling in the rest of the line on the second pass. This
scheme usually causes flicker. See also noninterlaced scanning mode.
Invar shadow mask
A special type of shadow mask, made out of Invar and alloy, that is able to withstand the
high temperature generated by the electron beam. The Invar shadow mask allows the CRT to
generate a brighter image than with the conventional shadow mask. An advanced Invar shadow mask
improves brightness by 40 percent over the standard.
ISO 9241 part 3
An ergonomic standard that covers hardware, software, workplace, and
environment. It addresses the actual application at the work place. The objective of part
3 is to ensure that the CRT display shall be legible, readable, and comfortable in use.
Liquid crystal display. LCDs use two layers of polarizing material separated by a liquid crystal solution. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, controlled individually, acts like a shutter. Color LCDs use two basic techniques for producing color: Passive matrix is the less expensive, and active matrix, also called Thin Film Transistor (TFT), provides a sharper image.
The degree to which the actual location of a pixel on the screen corresponds with its
intended location. Nonlinearity causes screen images to be more distorted in one area of
the screen than in another. This is sometimes caused by poor voltage regulation in the
magnetic field effects (MFE)
A monitor is affected by magnetic fields. When a screen develops wrong colors in certain
areas, or the picture becomes distorted, check what is located near the monitor. A steel cabinet, desk, bench, or steel girder imbedded in a wall or
ceiling could cause distortion of the picture tube's electron beams due to an impeding magnetic
field. Moving the monitor approximately 3 feet away from the suspected source can clear
the problem, as can degaussing it. Speakers should also be considered as a possible source of
distortion, since they may also create a magnetic field when
In technical references, the word memory used by itself refers to random access memory (RAM).
A device that allows one computer to communicate with another over phone lines. Can be inside a computer
(internal) or external. All modern modems are also capable of sending and receiving faxes with the use of fax software.
A set of Swedish safety standards that covers the levels of magnetic and
electrical fields in both VLF and ELF ranges. The Swedish National Board for Measurement and Testing (SWEDAC) requires that products
sold in Sweden comply with MPR II. To measure emissions, a sophisticated test that screens out background
radiation must be in place. Since distance to the CRT and orientation of the measuring
device affects measurement, precise placement of the measuring device is essential and
difficult to repeat. In addition, the actual image displayed can have an impact on
emissions, so that a given set of measurements may not predict the emissions a user would
actually encounter. It is worth noting that there are no scientific studies
that conclude that measurements above MPR II levels are hazardous. See
also TCO95 and TCO99.
noninterlaced scanning mode
A scheme for assembling an image on the screen by painting all the lines in one pass, then
painting an entirely new frame. Noninterlaced scanning mode reduces flicker.
See also interlaced scanning mode.
operating system (OS)
The program that runs a computer. The operating system takes care of managing files and folders (such as renaming,
moving, copying, and deleting files). It also provides the ability to start the other software you have on your
computer. Operating systems also usually include many programs, such as a text editor, that are almost essential to
have on every computer.
Infrared-light emitting diodes (LEDs) and photo transistors used for touch-sensing in infrared (IR) touchscreens.
Used in infrared (IR) touchscreens. The touch frame contains two opposite rows of IR-light emitting diodes
(LEDs) and photo transistors, collectively referred to as opto-electronics, concealed behind an IR-transparent bezel.
Chemical compound that emits light when excited by electrons.
Abbreviation for picture element, the smallest element of the picture that can be
displayed on the screen. Each pixel contains one red, one blue, and one green phosphor.
PDF file (Adobe® Portable
A universal file format that preserves the fonts, formatting, colors, and graphics of any source document, regardless of
the application and platform used to create it. PDF is the open de facto standard for distributing formatted documents
over the Internet. PDF files are compact and can be shared, viewed, navigated, and printed using free Adobe Acrobat® Reader® software, downloadable from http://www.adobe.com.
Documents can be converted into PDF files with Adobe Acrobat software.
point of information (POI)
The location at a facility where visitors seek information.
point of sale (POS)
The location at a merchant's facility where customer make purchases.
A device placed in a merchant location, connected to the bank's system or authorization service provider via
telephone lines, and designed to authorize, record, and forward data for each
sale by electronic means.
Random access memory. In technical references simply referred to as memory. A computer's memory is not
like its hard disk, which is permanent storage. Memory can only store information while the computer is on; however, it
is much faster than a hard disk. A hard disk is a mechanical device, but memory is stored on computer chips, and
information can be accessed from anywhere on the chip almost instantly.
Number of times the screen can be redrawn per secondan ergonomic issue directly
related to long-term ease of use. A higher refresh rate means a less
"flickering" display, resulting in less eyestrain and fatigue. Bandwidth,
horizontal scanning rate, and vertical scanning rate work together to determine both the
resolution and refresh rate.
The number of pixels that can be displayed on a screen, specified as the number of pixels
in a horizontal line multiplied by the number of horizontal lines. For example, a resolution of 800 x
600 is 800 pixels running horizontally and 600 pixels running vertically-a total
of 480,000 pixels.
Radio frequency. It consists of electromagnetic waves at a frequency between audio and infrared, used primarily in radio and
Radio frequency interference. This interference in the operation of a device is caused by incompatibility with ambient
RF signals. See also EMC, EMI, and RF.
A standardized serial port for connecting a computer to peripheral equipment, such as a
printer, mouse, scanner, modem, or touchscreen.
screen size versus viewable
Screen size is the total size, measured diagonally, of the monitor screen before it is
placed in the monitor cabinet. Viewable image size is the size, measured diagonally, of
the monitor screen that can be viewed once it is in the cabinet.
The equivalent of dot pitch on aperture grille tubesthe distance between one stripe
and the next one of the same color, expressed in millimeters.
TCO95 and TCO99
A standard set by the Swedish Tjnstemännens Central Organization (TCO) in 1991. It is even more stringent than
MPR II, especially for alternating electric fields (AEF). Not only are the permitted field levels reduced compared with
MPR II, but the measuring distance is reduced as well. Ergonomic and ecologic requirements are included for
TCO95. For TCO99, it is expanded to include more ergonomic and ecologic requirements. See also MPR II.
Thin film transistor. See LCD.
The angle of the CRT with respect to the horizontal-mounting bracket of the
chassis. Tilt can vary, depending on the monitor's orientation to the earth's
magnetic poles. Monitor manufacturers orient and align their products in the eastern
direction. When the monitor is facing a north/south direction, there may be a slight
rotation of the image.
End products can be Listed by Underwriters Laboratories for expected safety concerns, The CNL/USL designation in
the certification indicates evaluation to U.S. and Canadian standards. Typical end products are desktop touchmonitors.
UR/cUR Recognized components
Component products can be Recognized by Underwriters Laboratories for expected safety concerns. The
CNR/USR designation in the certification indicates evaluation to U.S. and Canadian standards. Typical end products are
touchscreens, controllers, and kiosk touchmonitors.
Universal Serial Bus. An external bus standard that supports data transfer rates of 12
Mbps (12 million bits per second). A single USB port can be used to connect up to 127
peripheral devices, such as mice, modems, and keyboards. USB also supports Plug-and-Play
Describes an interface-Web site, equipment, process-that people find easy to use, or intuitive.
A Japanese standard for RF emissions developed by the Voluntary Control Council for Interference. The VCCI
marking on an end product indicates it has been tested for compliance with the VCCI program.
The number of times per second that a monitor can draw all the lines
on an entire screen. A higher vertical frequency or refresh rate will reduce
flicker, helping to reduce user eyestrain and stress.
vertical scanning frequency
In interlaced mode, the number of fields written to the screen every second,
expressed in Hz. In noninterlaced mode, it is the number of frames (complete pictures) written to
the screen every second (also known as refresh rate). A higher vertical frequency or
refresh rate will reduce flicker, helping to reduce user eyestrain and stress.
Video Electronic Standards Association, a consortium of manufacturers formed to establish
and maintain industrywide standards for video cards and monitors. VESA was instrumental
in the introduction of the Super VGA and Extended VGA video graphics standards with a
refresh rate of 70 Hz, minimizing flicker and helping to reduce user
eyestrain and fatigue. See also video graphics adapter.
video graphics adapter
A card with a character generator and an array of microprocessors that translate bit
information from the computer into displayable video signals for the monitor. These cards
comply with various standards that determine the nature of the quality of the display.
VGA, introduced in 1987,
was the first analog card. It offered still higher resolution than
enhanced graphics adapter (EGA)- 640 x 480 pixels
for graphics and 720 x 400 pixels for text-and a color palette of 256 colors. VGA could
also emulate EGA and color/graphics adapter (CGA).
Super VGA (SVGA), devised by VESA in 1989, offers
a resolution of 800 x 600 pixels.
XGA-8514A, introduced by IBM in 1990, offers a
resolution of 1024 x 768 pixels (interlaced) and a color palette of 256 colors.
Extended VGA (XVGA), introduced by VESA in 1991,
offers a top resolution of 1024 x 768 pixels (noninterlaced) and a refresh rate
significantly higher than that of IBM's XGA-8514A.
High-end graphics adapters, introduced
in the late 1990s for professional workstations, offer top resolutions from 1280 x 1024 to
1600 x 1280, horizontal line frequencies up to 90 kHz, and bandwidths up to 200 MHz.
video signal The output from the video graphics adapter incorporating the red (R), green
(G), and blue (B) signals and the luminance signal, or combinations of these signals, that pass to the
video input of the monitor.
viewable image size (VIS)
Actual maximum viewable image size is dependent upon the size of the plastic or bezel
around the CRT. Typically, the maximum possible for a "17-inch" monitor is
actually 15.75 inches, plus or minus 0.25 inch at the ends of diagonal measurement. VIS
differs from diagonal linear measurement.
Random access memory for storing video information. VRAM is a special purpose RAM with
two data paths for access rather than the one path of a conventional RAM. The two paths
let the VRAM handle two tasks simultaneously: display refresh and processor access. VRAM
does not force the system to wait for one function to finish before starting another, so it
permits faster operation for the video subsystem.