Typically, the touch-sensor is always fully optically bonded or laminated with the cover glass and the TFT-display attached with double adhesive tape on 4 sides. But sometimes is also motivated to laminate the TFT. In outdoor conditions with strong sunlight for example it will generate less inner reflections and accordingly improved readability. Since there is no airgap, there won’t be any dust particles or humidity inside. And finally, it will manage higher impact force.
For better sunlight readability we can also add AG treatment of the cover glass and/or increase the backlight brightness with long life LED’s and make custom LED driver board with dimming capability down to 1 nit.