• All sections
• F - Mechanical engineering; lighting; heating; weapons; blasting
• F21K - Non-electric light sources using luminescence; light sources using electrochemiluminescence; light sources using charges of combustible material; light sources using semiconductor devices as light-generating elements; light sources not otherwise provided for
• F21K 9/27 - Retrofit light sources for lighting devices with two fittings for each light source, e.g. for substitution of fluorescent tubes

Patent holdings for IPC class F21K 9/27

Total number of patents in this class: 358

10-year publication summary

Principal owners for this class