Position Detection Apparatus Signal Synthesis Error Reduction

The patent introduces a third periodic signal as an intermediary to mediate between the two original periodic signals. Instead of directly calculating the upper-level position signal from two phase signals (which amplifies errors), the system uses the third periodic signal as a reference to specify the position of finer periodic signals. This intermediary approach distributes and reduces the impact of phase errors, allowing accurate position detection over a wider range without error accumulation.

The patent segments the position detection task into multiple levels using periodic signals with different periods. By using a third periodic signal with a period longer than the first two, the system creates a hierarchical structure where each level contributes to the overall position accuracy. This segmentation allows the detection region to be extended beyond the limitations of individual periodic signals while maintaining high accuracy through the combined information from all three signals.

The patent implements a feedback mechanism where the third periodic signal provides reference information that compensates for phase errors in the first two periodic signals. The signal processing unit continuously compares and adjusts the phase relationships among all three signals, using the longer-period third signal as a stable reference. This feedback approach maintains absolute position information retention while actively correcting for phase error distortion caused by slit string misalignment or mechanical variations.