DISTANCE SENSOR, ALIGNMENT SYSTEM AND METHOD
FIG1A shows a part of an embodiment of a distance sensor in more detail
FIG1A schematically shows the MEMS device as a membrane having a membrane surface 12 that vibrates with an amplitude A. The membrane may have lateral dimensions in the order of a few micrometers to few hundred of micrometers. The membrane may for example have a circular membrane surface with a diameter in said range as the lateral dimension or a square membrane having an edge in said range as the lateral dimension. Also membranes having a form other than circular or square may be employed, e.g. rectangular or oval. More specifically, the membrane may have a lateral dimension in the range of 1-1000 micrometer, for example in the range of 20-500 micrometer, for example in the range of 50-200 micrometer.
embodiment
30
detection means
1
distance sensor
20
MEMS driver
40
processing device
10
MEMS device
['1. A distance sensor (1) for estimating a distance to a surface (Os) of an object (O), the distance sensor including a micro electric mechanical system , MEMS, (5) comprising a MEMS device (10) having a surface (12), denoted as MEMS sensor surface, to be arranged opposite the surface (Os) of said object (O) and a MEMS driver (20) for generating an ac driving signal to cause the MEMS sensor surface to vibrate,  characterized in that  it comprises a detection means (30) to determine a value of a property of a dynamic behavior of the MEMS (5) and a processing device (40) to estimate an average distance (h) from a measurement of the dampening of the MEMS sensor surface, as a measured distance (D 2 ) between the MEMS sensor surface (12) and the surface (O s ) of the object (O) based on the determined value for said property.']