Robot Arm Optical Teaching for Precise Substrate Transfer

The patent replaces conventional mechanical teaching methods with an optical detection system. A light source emits light that passes through or is blocked by the robot arm, and a light receiving unit detects the light intensity changes. This optical system substitutes for traditional mechanical encoders and sensors, enabling non-contact, high-precision measurement of rotation angles and arm position without mechanical wear or calibration errors.

The patent introduces light as an intermediary medium between the robot arm and the detection system. The light serves as a mediator that carries information about the arm's position and orientation without direct physical contact. By detecting light intensity variations caused by the arm blocking or transmitting light, the system indirectly measures rotation angles and axis positions with high precision.

The patent designs the light source and light receiving unit to serve multiple functions simultaneously. The same optical system is used for detecting rotation angles, specifying rotation axis positions, and verifying arm orientation during the teaching process. This multi-functional approach eliminates the need for separate sensors and measurement devices, reducing overall system complexity while maintaining high precision.

The robot arm itself serves as part of the detection system by blocking or transmitting light based on its own position. The arm's physical presence and orientation directly modulate the light signal, meaning the object being measured also contributes to the measurement process. This self-service approach eliminates the need for external calibration artifacts or additional measurement infrastructure.