The specification of response time reflects the reaction speed of a zForce AIR Touch Sensor.

Specification

Initial touch: 16-46 ms, at 33 Hz scanning frequency (default frequency in idle mode).

Continuous tracking: 10 ms, at 100 Hz scanning frequency (default frequency in active mode).

Increasing the scanning frequency decreases the response time.

Definition

Initial Touch

The specified response time for the initial touch starts from the instant an object is presented in the sensor's active area and stops when the sensor starts to send the first touch notification for this object. The specified response time consists of two numbers reflecting the best case and the worst case, with the average response time right in the middle.

The response time (t) can be calculated for different idle mode frequencies (f) can be calculated by the formulas below:

Best case: t = 16 ms

Worst case: t = 1/f + 16 ms

Average: t = (1/f + 32 ms) / 2

In touch applications, an object will be detected slightly before it reaches the touch surface, making the perceived response time shorter.

Continuous Tracking

After the first touch notification, the sensor will continuously track and send touch notifications to update the object position. The response time is therefore defined as the time between subsequent touch notifications.

The response time (t) can be calculated for different active mode frequencies (f) can be calculated by the formula below:

t = 1/f