Brightness is an attribute of visual perception in which an object appears to be radiating light. The brightness (or luminance) of an object, such as a display, can be characterized as the amount of light that passes through or is emitted from a particular area, at a given unchanging angle. The unit for brightness is candela per square metre(cd/m2). A candela per square meter is also commonly called a “nit”. Thus, the higher the number of nits, the brighter the display. If the rugged monitor you are purchasing will be used in direct sunlight then the brighter the better provided that the contrast ratio is still relatively high (>500:1).
The contrast ratio is a property of a display that is defined as the of the luminance of the brightest color (white) to that of the darkest color (black) that the system is capable of producing. A high contrast ratio is a desired aspect of any rugged display since it results in better image clarity.
The viewing angle is the maximum at which a display can be viewed with acceptable visual performance. Display viewing angles are typically measured and reported from four different viewing directions (left, right, up, and down) from the center of the display. A left viewing angle of 45 degrees, for example, indicates that the display can be viewed up to 45 degrees off center before the image starts to deteriorate. Larger viewing angles are more desirable since they allow the display to viewed from all sides and directions. Ensure that the viewing angle will be wide enough considering the position that the rugged display will be located in relation to the user before making a purchasing decision.
Display resolution is typically expressed as the number of distinct in each dimension that can be displayed. It is reported dimensionally in terms of width and height with the units in pixels. Resolution, when measured this way, can only be used to compare displays that are the same size, since this is not a measurement of pixel density. When comparing displays of the same size (8”, 10”, 12”, etc..) the higher the dimensional resolution the better the image. When comparing displays of different sizes, it’s best to think of resolution in terms of pixel density. If different sized displays have the same dimensional resolution, then the smaller display will have a higher pixel density and thus a better picture.
Display size it measured diagonally across the front of the display in inches. The screen of a 15” rugged monitor, for example, will measure 15” diagonally across the face.
Most displays have buttons for driving common functions like brightness, video inputs, or accessing the menu. Look for displays with large, illuminated, and easy to use buttons.
Displays are lit by backlights. The backlights can either be fluorescent tubes or LEDs. Historically, most displays used fluorescent tubes but LEDs are rapidly becoming the norm. LEDs are typically more reliable, run cooler, and use less energy than fluorescent tubes. Look for rugged displays with LED backlighting systems.
If your display is going to be used outdoors or in an area that is exposed to sunlight then you will want to purchase a sunlight readable display. Sunlight readable displays are modified with a special piece of cover glass that is coated with a thin film that allows the monitor to be viewed in direct sunlight. They are also designed with very bright backlighting systems (typically, greater than 1000 nits). Often film modification are required within the LCD to maintain an acceptable contrast ratio.
Make sure that the rugged monitor that you are purchasing is equipped with the proper number and type of video inputs. The video input connectors on the back of the display should also be high quality, military grade connectors.
Most rugged display manufacturers offer custom options on their products. If a function that you want is not available in a standard model then ask the manufacturer if they can add it as an option. Viewpoint offers several different options that further enhance the capabilities of our displays.
We probably don’t need to say much here. Just remember that you get what you pay for in terms of quality, service and warranty.
Make sure that the manufacturer offers some type of warranty. Obviously the longer and more comprehensive the warranty the better.