Common optical encoders are broadly classified into several main types.

　　Common optical encoders can be broadly classified into the following types:

　　1. Incremental Encoder

　　� (no translatable text) Features : An incremental encoder uses the photoelectric conversion principle to output three sets of square-wave pulses—A, B, and Z. The A and B pulses are 90 degrees out of phase, allowing easy determination of the direction of rotation. The Z pulse generates one pulse per revolution and serves as a reference point for positioning.

　　� (no translatable text) Advantages : It features a simple operating principle and structure, a long mechanical lifespan, strong anti-interference capability, and high reliability, making it well suited for long-distance transmission.

　　� (no translatable text) Disadvantages : It is not possible to directly output the absolute position of the shaft; the position must be calculated by accumulating pulse counts.

　　2. Absolute Encoder

　　� (no translatable text) Features Absolute encoders use natural binary or cyclic binary (Gray code) encoding to perform photoelectric conversion, enabling direct reading of position information.

　　� (no translatable text) Advantages It can directly output the absolute value of the angular position, with no cumulative error, and the position information is retained even after power is removed.

　　� (no translatable text) Disadvantages : Resolution is determined by the number of bits in the binary representation, and precision depends on that bit count.

　　3. Hybrid Absolute Encoder

　　� (no translatable text) Features : A hybrid absolute encoder outputs two sets of information: one set is used to detect the magnetic pole position and provides absolute positioning data, while the other set is identical to the output of an incremental encoder.

　　� (no translatable text) Advantage It combines the features of absolute and incremental encoders, offering greater flexibility and precision.

　　4. Resolver

　　� (no translatable text) Type : Although the resolver is also used for position sensing, it is an analog encoder, differing from the aforementioned digital encoders in its signal output format.

　　� (no translatable text) Features It operates on the principle of electromagnetic induction and outputs an analog signal, commonly used in applications that require high-precision position feedback but do not necessitate a digital output.

　　5. Sine-Cosine Servo Motor Encoder

　　� (no translatable text) Features It consists of an optoelectronic encoder disk with a central axis, featuring alternating transparent and opaque concentric tracks. By means of photoelectric transmitting and receiving elements, four sets of sinusoidal signals are generated and combined. This type of encoder enables the servo drive to achieve high‑resolution interpolation without requiring high‑frequency communication, thereby reducing hardware complexity, while also providing smooth startup and substantial starting torque.

　　1. Automated Control System

　　In automated control systems, incremental encoders play a critical role. They are used to measure and monitor parameters such as the position, speed, and acceleration of mechanical equipment, enabling precise motion control. By providing real-time, accurate position feedback, these systems can implement closed-loop control, ensuring that mechanical components move along prescribed trajectories at specified speeds.

　　2. Machining

　　In the field of machining, incremental encoders are widely used in high-precision equipment such as CNC machine tools and machining centers. These encoders can accurately measure shaft rotation angles and linear displacements, providing precise motion‑control signals to the machine tool. When integrated with a CNC system, incremental encoders enable sophisticated path planning and fine position control, thereby enhancing machining accuracy and efficiency.

　　3. Robotics

　　Robotics is also one of the key application areas for incremental encoders. In robotic systems, incremental encoders are mounted at critical locations such as joints to measure joint angles and rotational speeds, thereby providing precise position feedback. This feedback is essential for enabling robots to achieve accurate control and perform complex tasks. By continuously monitoring and adjusting the robot’s position and orientation in real time, incremental encoders ensure that the robot follows its intended trajectory and speed, successfully completing a wide range of high‑precision operations.

　　4. Manufacturing

　　In the manufacturing sector, incremental encoders are widely used in various equipment and systems along production lines. They can measure conveyor belt speed and position, detect product location and orientation, and more. By providing precise positional and motion data, incremental encoders enable automated production and fine‑grained control, thereby enhancing both production efficiency and product quality.

　　5. Automotive Industry

　　The automotive industry is also one of the key application areas for incremental encoders. In both vehicle manufacturing and driving, incremental encoders are used to measure critical parameters such as engine speed, wheel speed, and brake pedal position. These measurements are essential for achieving precise control and adjustments. For example, in vehicle stability control systems—such as ABS and ESC—incremental encoders can monitor wheel speeds and steering angles in real time, providing the system with accurate motion data and helping to enhance vehicle safety and stability.