Photo Eye Sensor

A photo-eye sensor (also called a safety beam, safety sensor, or reversing sensor) consists of two units—a transmitter on one side of the door and a receiver on the other—mounted approximately 4 to 6 inches above the floor on the vertical track bracket or jamb. The transmitter emits a continuous infrared beam; the receiver monitors whether that beam is intact.

When the garage door opener begins closing the door, the photo-eye system activates. If any object, person, or animal breaks the infrared beam, the receiver sends a signal to the opener's logic board, which immediately stops the door and reverses it to the open position. The sensor is most effective against objects that intercept the beam at the height of the sensors—which is why the mounting height is set low enough to detect a small child or animal near the floor.

Photo-eye sensors became a federal requirement in the United States in 1993. Under the UL 325 standard, all residential garage door openers must include an entrapment protection device, and photo-eye sensors are the near-universal solution. A garage door opener that was installed before 1993 may not have sensors, and sensors can be added to most older openers as a retrofit.

Common photo-eye problems include misalignment (the beam is not reaching the receiver), sunlight interference (direct sunlight on the receiver mimics the beam and confuses the sensor), and dirt or spiderwebs on the lens. Most sensors have indicator lights that show whether alignment is good: a steady light usually means the beam is intact, while a blinking or red light indicates the beam is broken or misaligned.