counting Object Recognition Retro-reflective photoelectric sensor E3JK-R4M1

The mirror reflective photoelectric switch integrates the emitter and receiver into the same probe. During operation, the emitter continuously emits a modulated light beam (usually infrared light). Directly opposite the sensor, a dedicated reflector (also called a retroreflective plate or prism) is installed.

After the light is emitted towards the reflector, the reflector accurately reflects the light back to the receiver along the original path. When the object being measured enters the light beam path, blocking the emitted or reflected light, the light signal received by the receiver weakens or disappears, thereby changing the sensor's output state and achieving "object detection."

Simple process: Light emission -> directed towards reflector -> reflected back along the original path by the reflector -> normal reception by the receiver -> object enters and blocks the beam -> receiver's light signal weakens -> output is triggered.

1. Single-side wiring, long detection distance: The sensor only needs to be installed on the detection side, making wiring convenient. Its effective detection distance is usually much longer than that of diffuse reflective types (ranging from a few meters to tens of meters), approaching through-beam performance.
2. Stable detection, strong anti-interference: The reflector has very high and consistent reflection efficiency, unaffected by the surface characteristics (color, material, shape) of the measured object, as long as the object is opaque and can block light. The sensor typically emits modulated light (pulsed light at a specific frequency), and the receiver is only sensitive to reflected light at the same frequency, effectively suppressing interference from ambient light (such as sunlight or lamp light).
3. Requires installation of a reflector: A reflector needs to be installed and fixed on the opposite side, adding one extra component compared to diffuse reflective types. During installation, the sensor and reflector must be properly aligned.
4. Avoid false detection of transparent/reflective objects: For mirror-like or highly reflective objects, light may reflect back to the receiver, causing a "no object" misjudgment. Some advanced models include a "polarization filter" function to address this issue.