Preparing content for an LED screen is a familiar process. The main difference designers and content providers need to be aware of are the following:
– Screen Dimensions in Meters and Pixels
– Viewing distances
– Screen Pixel resolution
LED screens are typically designed for long distances viewing, anything from 3m – 300m. A 2m wide screen can be seen from 1 km away but is hardly readable in the normal sense irrespective of the screen’s pixel resolution. Likewise a 20mm screen viewed at 5m irrespective of width is not clearly understood.
Typically for most applications a 2m x 2m LED screen might be seen to be the minimum size give take a bit. In addition screens can be built to sizes that the project dictates or budget allows.
A 20mm pitch 2.8m Wide x 1.6m High screen would have a graphic prepared that measures 288 pixels x 160 pixels.
A 16mm pitch screen 2.048m W x 2.304m H would have a graphic prepared that measures 128 pixels x 144 pixels.
A 16mm pitch screen 1.92m W x 1.92m H would have a graphic prepared that measures 120 pixels x 120 pixels. In the desktop picture below is a 1028 x 768 pixel desktop with an LED screen window for a 20mm Pitch 2.8mW x 1.6mH Screen. The black area represents the LED screen and relative to a XGA 1024 x 768 pixel display.
A standard computer monitor measures 1024 x 768 pixels 72 dpi (dots per inch) so you can see that even though a monitor is substantially smaller it has a lot more pixels. Conversely a LED screen as described above is huge in comparison but has less pixels.
The more pixels within an LED screen means the image will be sharper the closer you are. A rough guide is 10mm Pitch = 10m viewing, 16mm pitch – 16m. This is the viewing distance that can be said the be the closest distance to the screen and the eye is unable to resolve the individual pixels – that is the image is not appearing pixilated.
The finer the pitch (3.5mm) typically means the text can be smaller on the screen and still be readable. However if the viewer is to far from the screen they will not be able to read it clearly as it will be too small.
The more coarse the pitch the larger the text needs to be relative to the screen size so it can be read and understood clearly.
For video the more coarse the screen pitch, the further the viewer needs to be from the screen to see a good quality image, finer the pitch the closer the view can be and receive a good viewing experience. Typically video demand either a finer screen pitch or further viewing distance compared to say standard text.
The LED software is extremely flexible allowing a flexible range of computer files and media to be displayed.
The LED display window is also set with the same pixel parameters ensuring the graphics and the window match.
Typically this includes more than 10 kinds of supported files, including: Document files (TXT), HTM/HEML/MHT files, EXCEL files,
WORD files (DOC/RTF),
All kinds of picture files (BMP/JPG/GIF/PCX/WMF/ICO),
All kinds of media files (AVI/MPG/MPEG/WMV/ASF), VCD files (DAT), Flash files (SWF), RealPlayer files (RM).
You can choose background color, background pictures, background action, and more than 40 special techniques.
Also there are 4 effects you may use: line, speed, stay, and font.
Plus, more than 50 different types and speed of clearing you can select.
Additional software functions include:
– Clock display
– Temperature (requires thermometer sensor)
– Screen status can be scheduled
– All media can be scheduled to appear in a timed format.
– A variety of schedules can be set up to run in a daily programme.
– Running other software under the management of the LED software.
All video and graphics should be prepared in the pixel format as stated in the screen specifications.
The article is available for download.