Selecting the Right Touch Screen Monitor

Unlike LCD TV screens the touch-screen monitor does not include any video decode circuitry associated with decoding satellite or terrestrial TV signals. LCD monitors do not include an aerial input through analogue monitors will include composite or YUV input signals.

Industrial touch screen monitors are also designed to have a long lifetime of product availability.

Panel Sizes and Screen Resolutions
The monitor panels themselves are designed for industrial and commercial use but would not normally be used for home use. While home LCD TV screens tend to be centred on 22in, 32in or 42in sizes, industrial LCD monitors are available in a wide range of sizes and resolutions. The LCD monitors including touchscreens are typically available in sizes from around 4in up to 104 where very large screens are required. In smaller sizes expect resolutions to be of the order of 320×240 (QVGA) pixels. At 10 inches upwards panels are available with 800×600 (SVGA), 1024 x 768 (XGA) and 1280×1024 pixels (SXGA). High definition panels are also available from around 24in upwards as are widescreen formats.

Aspect Ratio
The aspect ratio of a screen is a ratio of its width to height. Historically, TV sets were designed with an aspect ratio of 4:3. More recently, with the advent of high-definition television, screens are now manufactured in widescreen 16:9 formats. True widescreen formats are available with resolutions of 1024 x 576, 1152 x 648, 1280 x 720, 1600 x 900 and 1920 x 1080 pixels.

Screen Brightness and Contrast Ratio
The brightness of an LCD monitor is also known as luminance, measured in candela per metre squared. A typical computer monitor will have a luminance around 300cd/m2. Industrial touch screen monitors are designed with higher brightness levels for use in signage applications. Also, by adding a touchscreen to the monitor, the luminance levels can be reduced by 10% or more. When looking at technical data for luminance levels of screens you may also see a screen as having a brightness of 400nits which is the same as 400cd/m2.

Contrast ratio is a ratio of the luminance of the brightest colour (white) displayed on the screen against the darkest (black) displayed.

Input signals
Digital touch screen monitors normally come with VGA and DVI inputs as standard and with the option to include one or more HDMI interface inputs.

Output signals
With an HDMI input to the touchscreen monitor, the video and audio are provided via the HDMI link. The monitor may have speakers integrated into the housing but there are times where you may want to drive additional speakers external to the monitor or to provide a headphone output for your users.

Chassis Styles
LCD monitors are designed for industrial applications and as such come in a variety of chassis options. Most of the chassis options also include VESA-75/100/200 style holes for mounting to a standard off-the-shelf LCD bracket.

Rackmount touch screen LCD monitors are designed with mounting holes and a front panel such that they can be fitted into a 19in or 23in rack, with other sizes also available. The rack mount LCD monitor is offered up to the front of the rack and slotted in place.

Chassis mount touch screen monitors are fully enclosed and can be used as stand-alone displays. This style of a monitor is often used for digital signage applications. Chassis mount monitors can also be fitted to be flush with a bezel formed from a studded wall or another flat surface.

Open-frame touch screen monitors are designed to be mounted behind another piece of equipment or wall such that the screen is seen behind the wall. The open frame monitor has many mounting holes on each side for mechanical connection with a supporting face.

Panel mounted monitors are similar to the rack mount monitors as they are mounted into a hole. The panel monitors have a bezel as part of the chassis design so as to provide an attractive surround to the screen when fitted into a wall or other flat surface.

Driving multiple monitors
Whether your monitor uses VGA, DVI or HDMI inputs there is a range of digital video distribution devices available on the market. The distribution boxes take one (or more) inputs and provide 2 or more outputs which are in sync with each other. Distribution boxes are a solution where you need several monitors to all display the same synchronised content at various locations.

Touch Screen Technologies
Smaller panels are available with a wide choice of touchscreen technologies including resistive, surface capacitive, SAW and infrared available for very large screens. Thru-glass projected capacitive touch screens can be used for applications in retail where a user can use the monitor inside the shop while standing outside the shop window.

Other things to consider
Touchscreen monitors designed for industrial applications are also available with other options not normally available on computer monitors. Proximity detectors to turn the screen on, privacy filters and Transflective displays for outdoor use in bright sunshine are just some of the many options available when using industrial touch screen monitors.