Single Optical Sensor for Reverse Rotation Detection

The patent applies asymmetry by creating an asymmetric reflected light pattern on the rotating shaft through a specific groove configuration. The groove is positioned at a precise angular location and has a specific depth that creates an asymmetric reflection pattern. This asymmetric pattern allows a single sensor to distinguish between forward and reverse rotation directions by detecting the phase or position of the reflected light pattern, thereby achieving reliable direction detection without requiring multiple sensors or complex mechanical configurations.

The patent replaces conventional mechanical or audible warning systems with an optical detection system. Instead of using mechanical sensors, switches, or audible devices that require physical contact or complex mounting arrangements, the invention uses a single optical sensor to detect the reflected light pattern from the shaft. This optical system is non-contact, can be installed remotely from the shaft, and requires minimal modification to existing machinery, thereby greatly easing retrofitting while maintaining detection capability.

The patent utilizes optical reflection principles to create a light pattern that varies in intensity and phase as the shaft rotates. The groove on the shaft modifies the reflected light pattern, creating distinct optical signatures for different rotational directions. By analyzing these optical changes - specifically the phase position or intensity variation of the reflected light - the single sensor can precisely determine the direction of rotation. This optical encoding method provides sufficient precision for direction detection while maintaining the simplicity of a single-sensor system.