Method and device for detecting the edge of an object

A detection device having a micro controller for compiling signal course and storing signals to determine a threshold value edge point for detection (48) of an edge of an object, the detecting device comprises:

• a circuit board comprising:
• an emission region having a plurality of light sources arranged along a first straight line in a plane at equal distances apart and having a length extending up to a first end of the emission region,
• a receiving region having a plurality of individual readable photodiode regions, the receiving region running adjacent and parallel to the emission region along a second straight line in the plane,
• a common sector formed by at least one emission subregion being selected from the emission region and extending up to the end of the emission region and an adjacent parallel at least one receiving subregion being selected from the receiving region, when the at least one emission subregion is activated in the common sector, the receiving subregion in the common sector is simultaneously activated,
• the at least one emission subregion having at least one light source, the receiving subregion receives a reflected light from the object as a light signal,
• an opaque separator located in a recess on the circuit board,
• a multiplex chip located on the circuit board being adapted to control the light sources in the emission subregion and to transmit light from the emission subregions.

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.