Patent ID: 11906284
Assignee: BALLUFF GMBH
Field: Measurement (Instruments)
Classification: CPC G  B | IPC G

Claim 7:
8. Method for detecting an edge of a silicon wafer by means of a detection device having no lens and sized for inclusion in a blade of a transport system, the detection device comprising a micro controller for compiling a signal course and storing signals to determine a threshold value edge point of the silicon wafer, a frame having a recess defining a plane, an emission region running along a first straight line in the plane and a receiving region running along a second straight line in the plane and arranged parallel to the first straight line, the frame further having a divider arranged orthogonal to the plane and separating the emission region and the receiving region and:
wherein, the emission region includes a plurality of emission subregions each emission subregion including at least one light source;
wherein, the receiving region includes a plurality of receiving subregions;, the method comprising:
a) selecting an emission subregion of the emission region, wherein the selected emission subregion has a length along the first straight line in the plane and extends up to a first end of the emission region in the plane;
b) forming a common sector selecting a receiving subregion adjacent and parallel to the selected emission subregion, wherein the selected receiving subregion has a length along the second straight line equal to the length of the emission subregion along the first straight line,
c) emitting light from the selected emission subregion,
d) receiving a light signal of light reflected on the object only in the selected receiving subregion and storing the light signal,
e) shifting the selected emission subregion along the first straight line in the direction of a second end of the emission region and shifting the selected receiving subregion along the second straight line from a first end in the direction of a second end of the second straight line, simultaneously activating the emission subregion and the receiving subregion in the common sector,
f) repeating steps c to e until the emission subregion extends up to the second end at the start of step e,
g) after step f, compiling a signal course from the light signals received in step d, and
h) carrying out the detection of the edge of the silicon wafer from the signal course.