Patent ID: 10908334

Abstract:
An infrared illumination and detection system can include an infrared light source that can emit infrared light having a first wavelength. A visible light source positioned adjacent the infrared light source can emit visible light that overlaps the emitted infrared light. An infrared detector assembly, positioned adjacent the infrared light source and the visible light source, can include a wavelength-sensitive filter that can block wavelengths away from the first wavelength. The infrared detector assembly can include a sensor that can sense light at the first wavelength. The emitted infrared light can appear red when viewed by the human eye in the absence of the emitted visible light. The emitted visible light can optionally be sufficiently bright so as to substantially eliminate viewed redness when the infrared light and the visible light are viewed, together, by the human eye. Alternatives to reduce or eliminate the perceived redness are also provided.