Definitions: On-Glass vs. Frame-Based Construction
“On-Glass” and “Frame-Based” are the two dominant methods of construction. On-Glass construction uses a touch sensor substrate placed directly on the surface of an LCD panel within the monitor. The user actually touches the touch sensor itself.
Frame-Based construction, in sharp contrast to On-Glass, places touch-sensing components in a mechanical frame, which is then placed over the display or around the active viewing area of the display.
Choosing On-Glass or Frame-Based influences directly the touch technology which may be employed. On-Glass is typically used to build a solution using Surface Acoustic Wave (SAW), 3M DSTTM Dispersive Signal Technology, and both Projected and Surface Capacitive touch technologies.
Frame-Based construction is commonly associated with Infra-Red touch technology and Optical (e.g., camera-based) technology.
Digital Signage and Multimedia Application
Determining the best fit for our application means first choosing the best solution, which first involves construction method, which in turn refines the touch technology, or touch sensor technology, available to us.
On-Glass construction is very well understood by military, ATM, industrial, casino, gaming and a variety of other markets. New or developing markets and applications such as digital signage have yet to acquire enough experience to understand the distinct advantages of On-Glass construction.
A primary example of historical preference exists in the gaming and casino markets. The selection criteria for these markets are much the same as for digital signage, including 24/7 continuous operation, high volume public access, repetitive use and sustained abuse, highest quality image standards, and finally a significant exposure to financial risk to technology failure.
It is conservatively estimated that more than 85% of all touch displays employed in the gaming and casino industry are On-Glass construction. Frame-Based solutions remain a small percentage of total applications. Distilled to one word, On-Glass construction has field-proven reliability.
Advantages of On-Glass vs. Frame-Based Construction
On-Glass construction uses lightweight, thin sensor substrates that fit into the manufacturer’s original display bezel, adding a layer of protection and strength, preserving the original factory design, function, identity brand equity with zero compromise.
On-Glass construction allows for 100% of the active touch area in the original factory display enclosure, affording a seamless design so that touch operability is free from impairment from blocking by foreign objects.
Leading manufacturers of On-Glass touch sensors use thin, lightweight and chemically strengthened or safety glass to satisfy UL® requirements for strength and breakage.
In contrast, Frame-Based solutions that are packaged with a mechanical frame must first be placed on a glass substrate to provide a “rigid” touch surface.
Frame-Based solutions have frames that are already thicker than the “On Glass” solution itself. When joining Frame-Based solution frames with the rigid touch substrate, the resulting solution almost always is too thick to work within the factory enclosure. As a result, the Frame- Based solution typically must replace the OEM factory enclosure.
With Frame-Based touch sensors the required replacement bezel often compromises the LCD OEM’s brand by either being totally discarded with a replacement bezel or covered by a secondary bezel, both which risk association with poor performance through loss of brand recognition. In addition, the manufactured replacement bezel can obscure performing components such as front
control sensors or connections.
In addition, the manufactured replacement bezel is more likely to introduce “fit” gaps, leaving it open to collect debris or allow build up
of dust and dirt, all of which can impair touch operation. In the case of Infra-Red touch sensors, the IR components are packaged in a
frame. The frame is exposed, leaving it open to collect debris or allow build up of dust and dirt, all of which can impair touch operation.
The type of construction method utilized greatly influences the resulting interactive display. On-Glass construction provides virtually seamless integration of a touch sensor within the manufacturer’s original display housing, yielding a product that looks and functions exactly like the LCD display. Get the complete white paper on On-Glass vs Frame-Based Construction here.