This section of our site is designed to help you, the user, learn any confusing terminology you may have come across. If you would like us to add something, please Contact Us, and we will add it!
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Back light
In LCD displays, the
screen does not produce light by itself; it needs a back light bulb to
make the display visible. The back light bulb sits behind the display,
and when powered on shines brightly, making the display visible. A
common example is a digital watch; you can read the display in the
sunlight, but in a dark room, you can not. When you press the glow, or
light button, then the watch face lights up so you can read it. The
light you are seeing is being produced from a back light.
Pictured to the right are two different back light bulbs for the Allen Bradley 550
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Burn-In
Burn in is a common
occurrence in CRT monitors. When a static image (that is, non changing)
is displayed for a long period of time, the pixels are actually burnt,
leaving a shadow of the image etched into the glass. A common example of
a static image on your computer would be the start menu button; even
though the images on the screen change all of the time, the start menu
button is always present. On an old display, it is very common to see
the start menu button burnt into the glass.
Pictured to the right is an old display with a burnt in "shadow" image
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Controller
In an industrial
setting, a controller is an entire unit, commonly composed of (but not
limited to) a computer, a display, a hard drive, a mouse, a keyboard,
and a touchscreen. All of these components work together to produce the
desired result, such as controlling a CNC machine.
Pictured to the right is an Allen Bradley MP20 controller, complete with a display, a keypad, and a computer (not shown)
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CRT
Cathode Ray Tube. These
displays are based on very old technology (the first CRT television was
produced in 1934!). These displays are bulky, and are characterized by a
slightly curved screen. Some CRT units are available with a flat
screen; these should not be confused with LCD's. CRT monitors excel when
they are used in monochrome applications; they display different shades
of grey extremely well. This is very apparent when used in medical
imaging equipment. We can supply replacement CRT displays if they are
requested. These displays are prone to burn-in after a long period of
operation.
Pictured to the right is a Monitech Cathode Ray Tube
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Frequency
The frequency is the refresh rate of the display. It is directly
related to the resolution of the screen; the higher the resolution, the
faster the refresh rate. For example, VGA has a frequency of 32 kHz
(kilohertz), and a resolution of 640 x 480, while XGA has a frequency of
54 kHz and a resolution of 1024 x 768. The benefit of having a higher
frequency is that the screen can display the image faster. On a
resolution that has 480 vertical pixels, it takes 32 microseconds for
each line of the 480 pixels to display the image. On a display with 768
vertical pixels, it only takes 18 microseconds to display each line.
Therefore, higher resolutions, frequencies, and refresh rates are desired
if you are using the display in a high motion application, such as
video gaming, or precision engineering.
The image on the right, and description below are courtesy of Wikipedia.
"Three cyclically flashing lights, from lowest frequency (top) to highest frequency (bottom). f is the frequency in hertz (Hz), meaning the number of cycles per second. T is the period in seconds (s), meaning the number of seconds per cycle. T and f are reciprocals."
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LCD
Liquid
Crystal Display. These displays are based on a much newer technology; by
comparison, the first LCD television was not introduced until 1983.
These are the traditional "flat screen" displays. With an average
thickness of 3" as opposed to 14" (cathode Ray Tube), a more accurate
description would be "slim screens". These monitors are superior to
alternatives for several reasons; the cost is lower, the technology is
more reliable, they are immune to burn in, and replacement is easier.
Monitech manufactures LCD replacements for many different applications,
for many different makes and models.
Pictured right is a Monitech LCD display (profile view)
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Legacy
The term Legacy is used
to describe any old technology that is still in use. For example, NASA
uses equipment from the 1970 still, because it still works. The old
adage is true; if it aint' broke, don't fix it. The same holds true in
industry; there is no point in replacing a million dollar machine simply
because it is outdated (As long as it still works). One of the common
problems with working with legacy equipment is that repair or replacement
parts are either rare or non existent, and many modern products will
not interface with legacy equipment properly. Monitech has solved that
problem; our displays are specifically designed to work with legacy
equipment.
Pictured right are some legacy monochrome displays
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Low Scan
A low scan display is any display with a frequency of under 32 kHz
(kilohertz). 32 kHz is the industry standard. Modern displays are not
compatible with old video signals, and as such, customers are forced to
use old technology when their display fails. Monitech monitors are
designed to work with low-scan applications, so you can get the
reliability of an LCD on a machine that would not otherwise be able to
support it.
Pictured on the right is an old KME legacy style connector
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Monitor
Another
common name is "display". When you think of a monitor, think of the
thing you are reading this on. It can be the display on a television,
computer, phone, or even a GPS. Many of our customers are not sure
exactly what the term monitor means. The monitor is the actual screen,
nothing more, nothing less. The touch screen is a separate component, as
is the computer it is connected to. If it is being used in an
industrial setting, then the monitor is one part of the entire
controller. The computer of the controller is separate.
Pictured on the right is a Monitech replacement display for a CIncinanti Milacron 950 with a frame
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Monochrome
This
means that the display only produces one color. These colors are
commonly green, red, amber, or white (as well as black). For example, an
old "black and white" television was monochrome; it produced black,
white, and all of the shades of grey in-between. These are still common,
as they are cheaper to produce.
Pictured on the right is a monochrome green display
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Pixel
A pixel is a group of three colored dots; red, green, and blue. By
changing the intensity of these three colors, every color in existence
can be produced. If the intensity of all 3 colors was set at 0, you
would see black. If red and green were set at 0, but blue was set at
max, you would see blue. If all three colors were set at max, you would
see white. Cheaper LCD screens can actually have pixels become blocked,
(generally by dust), which will cause them to appear as black dots.
Pixels can also burn out, but this is not very common.
Pictured on the right is a closeup of pixel groups on an LCD display. Photograph courtesy of Wikipedia
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Resolution
The resolution of a
screen refers to how many pixels are running across the length and
height. For example, a resolution of 800x600 has 800 pixels along the
width of the display, with 600 pixels going up the height. This makes
for a screen total of 480 000 pixels. The higher the resolution, the
sharper the image on screen, as more detail can be shown. The most
common desktop resolution is 1024x768, while the most common industrial
resolution is 640 x 480. This is because a computer is typically
displaying much more information, and the extra resolution is simply not
needed in industrial applications.
Pictured right is a comparison of video signals and corresponding resolutions. Photograph courtesy of Wikipedia
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Touchscreen
A
touchscreen is a separate component from a display. Essentially, it is a
piece of glass or plastic that goes in front of the display and accepts
input from the user. It can either be flush with the display (like in a
touch phone, or a GPS), or it can be a few inches in front of it (like
on an ATM / ABM). There are hundreds of different types of touchscreens,
from many different manufacturers. At Monitech, we can replace many of
them; please contact us and let us know what it is you need.
Pictured right is a touchscreen for an Allen Bradley display
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Video Connector
The
video connector is what sits on the end of the video cable, and what
plugs into the display and the computer. There are many different types
of video connectors, from VGA to BNC. The most common is probably right
in front of you; the blue VGA cable that plugs your computers display
into your computer. Since there are so many different types of
connectors, we have built a database of which displays use what
connector. For example, we know an Allen Bradley 1400e will always use a
VGA connector.
Pictured on the right are two different connectors, on the right is a VGA, while on the left is a 15 pin low density connector
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