Projected Capacitive Sensor Technology

Using glass substrate, ITO conductive coating and a polymer film sheet, projected capacitive systems utilize more complex electronics and sensor construction when compared to other technologies

As indicated in the image above, the conductive coating is "etched" to make a "pattern" with the ITO coating to form a grid. This can be a single layer with an X-Y grid, or a dual layer, the first being one etched series of lines forming an X-axis and then a second layer perpendicular to the first to form a Y-axis.

Applying a touch force measures electrical patterns between the adjacent patterns in the conductive coating.

This method is most frequently recognized in popular cell phone applications wherein the touch surface is flush with the surrounding bezel. Optical clarity is typically good, averaging approximately 85% light transmission.

 

Projected Capacitive: Key Points

• good to very good opitcal clarity
• all-glass top surface solution
• bare finger, thin-gloved finger or conductive stylus touch
• in-bezel and flush surface design construction
• durability is proportional to quality, chemical strengthening construction of cover material
• lamination of lens substrate can provide shard containment
• more complex construction than other technologies, sometimes resulting in comparatively higher cost