The **E39-R40** is a specialized electronic optical component, specifically a **Retroreflective Reflector** (often referred to as a "corner cube" reflector) manufactured primarily by **Omron Industrial Automation**. It is designed to work in tandem with photoelectric sensors. --- ## 1. Technical Specifications The E39-R40 is part of the E39 series of reflectors. It is characterized by its compact, rectangular shape and high reflectivity. | Parameter | Details | | :--- | :--- | | **Type** | Retroreflective Reflector | | **Material** | Methacrylic resin (Surface) / ABS (Base) | | **Shape** | Rectangular | | **Reflective Surface Size** | Approx. 40mm x 10mm (Slim profile) | | **Mounting** | Adhesive backing or screw-mount holes | | **Compatible Sensors** | Retroreflective Photoelectric Sensors (e.g., E3Z, E3S series) | --- ## 2. Key Electronic & Optical Components While the E39-R40 does not contain active electronics (batteries or circuits), its "electronic" function is defined by its **optical properties** within a sensing circuit. ### A. The Corner Cube Microstructure The internal surface is molded with thousands of tiny "corner cubes" (triangular pyramids). * **Function:** When a beam of light from an emitter hits these prisms, it reflects exactly **180 degrees** back to the source, regardless of the angle of incidence (within a certain range). * **Electronic Integration:** This allows the sensor's receiver to detect a broken beam when an object passes between the sensor and the E39-R40. ### B. Polarization Properties The E39-R40 is often used with **Polarized Retroreflective Sensors**. * **MSR (Mirror Surface Rejection) Function:** The reflector rotates the polarization plane of the light. The sensor's receiver is tuned to only "see" this rotated light. This prevents the sensor from being "tricked" by shiny objects (like a soda can) that might reflect light back but without rotating the polarization. --- ## 3. Application Use Cases The E39-R40 is commonly used in environments where space is limited but high-precision detection is required. 1. **Conveyor Belt Systems:** Detecting the presence of boxes or components. 2. **Gate/Door Controls:** Safety sensors for automatic doors. 3. **Machine Tools:** Limiting travel distance of moving parts. 4. **Narrow Spaces:** Because of its 10mm width, it fits into rails and slots where standard square reflectors (like the E39-R1) cannot fit. --- ## 4. Installation Considerations To ensure the electronic sensor functions correctly with the E39-R40, observe the following: * **Sensing Distance:** The maximum range is typically reduced compared to larger reflectors (like the E39-R1) because the surface area is smaller. * **Alignment:** Ensure the reflector is perpendicular to the sensor beam for maximum signal strength. * **Cleaning:** Dust or oil on the methacrylic surface will significantly degrade the "Reflector Factor," potentially causing "false-off" signals in the sensor circuit. ---