| 主权项 |
1. A fluid cylinder comprising:
a piston rod that is guided in a cylinder casing and on which a marking is provided with equidistantly arranged marks; and an optical sensor unit directed toward the marking, wherein the optical sensor comprises two or more equidistantly arranged optoelectronic sensor elements, each of which are configured to generate a binary output signal, wherein the axial spacing between the optoelectronic sensor elements and the marks is dimensioned such that each binary output signal comprises a predetermined phase shift relative to the chronologically following output signal, and the marking has at least one reference mark for which an output signal exists in all of the optoelectronic sensor elements, and wherein the optical sensor unit comprises an error detection which converts the incoming binary output signals from the optoelectronic sensor elements into a Gray code and, if there is a change in the output signals by more than one bit, recognizes a faulty signal, and if all the sensor elements respond, recognizes the at least one reference mark. |
