Touch trigger probe with capacitive sensor

A touch trigger probe for tactile measurement of coordinates of an object, the touch trigger probe comprising:

• a probe tip with a tip center (C) and
• a capacitive sensor having a sensor base and a sensor head which is spaced to the sensor base by a flexible suspension and can be capacitively coupled to the sensor base,
• whereby the sensor head follows a displacement of the probe tip center (C) when contacting the object with the probe tip,
• wherein the suspension is designed to enable a relative movement in three degrees of freedom of the sensor head with respect to the sensor base when contacting the object with the probe tip in such a way that there is a bijective map between these three degrees of freedom sensed by the capacitive sensor and all three translational degrees of freedom of the displacement (d) of the probe tip center (C),
• wherein the sensor base comprises electrodes (X+, X−, Y+, Y−) distributed in a lateral plane (xy) as multiple concentric arc segments (ai) at different radii, and
• wherein the sensor head comprises multiple conductive, circular, spaced protrusions for said capacitive coupling, being aligned to a respective arc segment (ai) or a pair of differential arc segments in the lateral plane (xy) when the sensor is in a rest position.