All Lighting And Detection Devices

This group gathers electrical engineering inventions that produce light or sense a physical condition and signal its presence, including the incandescent and fluorescent lamp, the laser, strobe light, traffic light and other lighting devices, the photocopier and Dreamachine that work by projecting or flickering light, and detectors such as the smoke detector, carbon monoxide detector, metal detector and security alarm. Their shared work is emitting light or detecting and signaling a condition, as distinct from the communication devices that carry a message and the circuit components that make up their internal electronics.