Optical Bonding improves display performance when using projective capacitive touch screens

Review Display Systems Ltd have introduced a range of TFT display panels which have Projective Capacitive touch sensors optically bonded to the panels. Standard screen sizes include 15, 17 and 19 inch with more sizes to follow shortly. The optical bonding of the touch screen dramatically improves display system readability in applications where the ambient light levels are high.

Many applications experience display readability problems when operating in high ambient light levels and this is made even worse if the application requires some form of touch screen device to enable data input to the system. Whilst display manufacturers have worked hard to improve the TFT display performance in this situation with Anti-reflective films and improved brightness backlights, the use of a touch screen can negate the improvements, especially if a resistive touch screen is used, as this can have up to four reflective boundaries between the front layer and the screen. Using Projective Capacitive touch technology reduces the number of construction layers and with the Optical bonding we ensure that no air gap is present. The result is a significant improvement in readability of the screen in all ambient light levels. Optical bonding involves using a process to fill the air gap between the front of the TFT LCD and the rear of the touch screen with a material that has a similar refractive index this reduces reflections since the difference in the refractive index between layers is reduced. Standard display screen sizes include 15, 17 and 19 inch with more sizes to follow shortly. The projective capacitive screen features a surface hardness of 5 or higher Mohs, making more difficult to scratch than a resistive panel, touch resolution is 2048x2048 points and the interface to the host system is via a USB interface. Operating temperature is -20ºC to 80ºC, ideal for industrial applications; the panel will also support multi-touch operation within the Window 7 environment.