What does the Ruby2 touchscreen detect to maintain functionality?

The Ruby2 touchscreen utilizes infrared beams to maintain its functionality. This technology relies on a grid of infrared light beams emitted across the screen's surface. When a user touches the screen, the interruption of these beams is detected, allowing the device to recognize the location of the touch accurately. This method is effective because it enables multi-touch capabilities and provides a responsive user experience without reliance on pressure sensitivity or physical contact mechanisms.

The other methods listed do not apply to the Ruby2 touchscreen; for example, it does not utilize touch pressure, which is more common in resistive touchscreens. Similarly, voice commands and heat sensors are not functions associated with the Ruby2 touchscreen, as it is designed specifically for tactile interaction using infrared technology.